My FH has two younger sisters (16 and 11) who are two of my bridesmaids. I'm not close with them but I've honestly been trying to get some one-on-one time with them to try to get to know them better. The problem is that they are both overly busy with school and sports and are young, so they don't know their own schedules well. For a while I was doing everything through their mother (my FMIL), but she's become very mean and rude towards me, so I'd rather communicate directly with the girls.
My other bridesmaid got her dress over the weekend, and it's not due to come in until June (the wedding is July 4), so I'm eager to get the two sisters in as soon as possible. I gave the girls the brochure from David's bridal about 3 weeks ago to look through and pick styles, and they know what colour to get, but they haven't even looked through it yet. I texted the 16 year old to let me know when this month they are free to go get their dresses, and she said they're busy every weekend with sports but she would check with her mum and let me know. I told her even a weeknight would be fine. She hasn't gotten back to me since.
Furthermore, a few weeks ago I asked if they were free the day after valentine's day so I could take them out for a galentine's day brunch. She said they were so I went ahead and scheduled it, and then two days ago she texted me to say that she actually had a swim meet that day.
They are only in the wedding because my Fiance wanted them to be and it's caused a lot of drama between me and their mother because she feels like I'm not fully including them in everything (long story, the two girls aren't upset about anything regarding that), and now it seems like they don't even care about the importance of their role. They're also going on a family holiday less than 2 weeks before the wedding, so they likely won't be a part of the pre-wedding week activities.
If they don't have time to hang out with me, that's fine. But if they don't get in to get their dresses soon then the dresses won't come in on time and I know that their mother will blame me for it.