Weddingbee boards

I'm in the process of picking my bridal party. I'm going to have 3 attendants and two of them will be friends of mine from high school and grad school. The third is a slightly trickier situation. There are two girls (16 and 19 at the time of the wedding) who I babysat for several years. They're like my little sisters and their parents are best friends of my own. I really want to ask the older one to be in the wedding party, but I'm really afraid of hurting the younger one's feelings. We really want even numbers of bridesmaids and groomsmen, so I don't really want to ask them both. (I'm also afraid she's a little too young.) I also don't really have a lot of close friends, so although I guess I could choose somebody else for the 3rd for the sake of avoiding conflict, I'd rather pick somebody close to me.

I'd like to ask her to be involved in the ceremony or the day in some way (doing a reading, attending the luncheons/fittings if she wants, etc.), and I'd like to send her the same little "Will you...?" package that the bridesmaids will receive. I'm just not sure what sort of honorary title I could give her or what I could do to make her feel special. (She's 15 right now.) I feel like my letter to her right now will read, "Hey, I love you like a sister, but because you're young you're not in the bridal party," and that's not what I want at all.

If anybody has any suggestions or has been in a similar situation, please let me know! 

Yeah, I'm trying to convince him, but I don't want to pressure him. Doing a reading is a great idea. I guess I could write something like, "I'd love to have you as an honored guest on my wedding day." We have zero clue about the ceremony right now, so I'm not sure what opportunities there will be to participate. Not as much "fun" as bridesmaid (if only she knew - ha!), but hopefully she'll be ok..

Oh, Pro, that's a *great* idea.