Junior Bridesmaid Help

Hi ladies! Our wedding is 15th of October this year, so really not long now to get things organised! My junior bridesmaid (13 years old) is my HTB's little sister and I'm currently trying to organise her JB shoes for the wedding. It took months to get the dress organised as my future mother-in-law was really dragging her feet and now she is doing the same with the wedding shoes. I asked her to get me the shoe measurements 2 weeks ago, still nothing. I asked by HTB to chase her for them over the weekend, again she said as the JB is only 13 it's better waiting to closer to the time. None of these people seem to appreciate how little time is left and aren't really helping me here! Any advice??? Preferably before I lose my patience