Congratulations!
I know that, when I was first initiated, I sometimes felt a bit like the odd one out. I didn't know a lot of the traditions, procedures, songs, etc. It may help your "little sis" if you guided her along as she learns Alpha Xi Delta's customs. For example, explain to her what to expect during formal meetings, how the Founders Day lunch normally goes, help her with the songs and so on.
Definitely make sure she gets plugged in to a nearby alumnae association so that she can start building friendships and enjoynig the sisterhood.
Congrats again!
.....Kelly