As a parent with a demanding job, I will get so distracted with life that I forget to reach back out. I even do it with family from time to time. I feel so bad that my brother reaches out to me more than I do to him.
I would just send a short message saying something supportive and non-judgmental. Like, "sorry I haven't reach out lately, things got busy (with my job/schoool/or whatever you do), just wanted to check and see how you are doing." Or something along those lines, to put the onus on you and easy her feelings if she does feel bad about not messaging you first. I would not immediately ask her to meet again. Just see if you can get the conversation going.