Yes she was young but probably unlike your little sister, mine is incredibly intelligent and mature (not trying to insult!) far more then I was at her age but when our father died when she was 8 she matured very quickly. She is also going to HAVE to be there with me for the majority of her life– unlike friends who, unless REALLY special, usually stick around for several years and get bored or you lose contact.

It was important to me to choose her, instead of my "best friend" for 7 years because I knew I would always have my sister, and in the end, she was the one who cared the most about me, not my friend. Now since then the 7 year old friend and I do not talk (would you believe it, we had a fight and stopped talking when she got an abusive boyfriend and I didn’t like him) and my sister loves my husband and me and ennjoys coming over. I still had other bridesmaids, she was one of them, and the rest of us still hang out and talk of course but my sister is always there and always will be.

Of course that is your choice. My 12 year old sister was escorted down the isle by our good friend, my husband’s Best Man whom he’s known since he was 3 (so practically brothers) and he was 27. Imagine her being uncomfortable in that situation!? Not my sister, poised and beautiful as ever and only 12.Just thinking about how mature she handled it was wonderful.

And we got our nails done together the both of us (she was not allowed to the bachlorette party though 0_0)

So while you may think it will be awkward, or weird, the people coming to your wedding are supposed to be the people you just can’t live without and if I had to choose again I would select my sister again and again. She may have been young a "junior bridesmaid" but she was the most important person there other then my mother and now mother-in-law and father-in-law. Doing anything else would have made her feel left out and I wanted her to know how special she was.

And all of my friends agreed, even the older ones.

Good luck!

EDIT: Oh and I involved all my friends and my sister in a lot of the process of my wedding. She and my bridesmaids were there with me when I picked out my dress, when I got my hair tried out and for many other things. She offered her input on the photographer and more. She even selected a special song for just me and my husband and contacted the DJ personally to make sure he selected it. She handled her toast better then the best man and was responsible for fixing my gigantic train at the alter. She really did a wonderful job, even my friends commented on how great she did.

And she does look older then her age and acts like it so it was a little iffy about the single guys that were coming. I just made sure that all my guests, since they are all close friends and family that I can’t live without, KNEW that she was 12 and not 16 and that she was incredibly young. I did not have a single nasty comment from anyone in regards to her and if possible, lol, she was PRETTIER THEN ME!
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A happy wedding day and a blessed marriage.

She’s a junior bridesmaid in the wedding, but her and her mother seem to feel it’s not "important" enough. FMIL wanted her to do a reading on top of it, but then it wouldn’t really be fair to the other bridesmaids either. They’re all equally important in my opinion (being in the bridal party is THE highest honor) and no one but the maid of honor should really be "elevated" past the others.

I would ask your sister what she wants to do – be a junior bridesmaid or do a reading. I would imagine that as a junior bridesmaid in your wedding, rather than your brother’s, she would automatically end up more included. It’s tough when the junior BM is the groom’s sister (for me, especially hard because she lives over three hours away from me and FH). Since your sister is the sister of the bride, it’s far easier to include in dress shopping and all that stuff…. the only thing she’ll need to realize is that she won’t get to do EVERYthing (ie bachelorette party).
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Are you going to stick a 25 year old man walking down the aisle with a child?? I am sure that they will love that.

EDIT: My two Junior Bridesmaids were 13 and 15, but they both looked older and were both over 5′9". I just about had a stroke when one of my single male friends asked who the two hot bridesmaids were!! LOL! If she looks older than her age, keep an eye out for the single guys that try to hook up at weddings!!
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Just have a ring bearer and a Jr. Bridesmaid. It will still be balanced and she will feel much better about her role. She can walk alone even if you are having groomsmen escort bridesmaids.
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At that time I will have a younger sister who is either 13-14 depending on the date and I am unsure of what role to give her in my wedding. There is a HUGE generation-like gap between us 11 yrs. I will be 24-25 when I get married, so we don’t have much in common, yet I want her to be involved.

The only Idea I have is her "escorting" my nephew who will be either be just a day or so short of 2 or 2 firm as my ring bearer. She wouldn’t be a flower girl, and I would pick out a dress similar to the bridesmaids for her, and I could have her in charge of my young nephew.

Aside from that are there any other suggestions?
She was a Junior Bridesmaid in my Brothers wedding and felt unimportant because she didn’t have an escort or really anything to do but stand there. I wanted to give her an actual job.
It may have been how my sister in law handled my sisters role in the wedding, the only thing she was able to do WITH the other bridesmaids was to get her nails done,and even then my mother was present. She wasn’t with us to get our hair done or get dressed, so she felt really left out. I am just torn.
HAHAHA No I am not going to do that especially since my groom is going to be 27, and at least 3 of his groomsmen are going to be 30. That would be awkward. It was strange enough for my brothers older friend escorting a 21 year old me, when he had seen me grow up.