Why would a 24(f) spend nearly all of her free time calling/FaceTiming me 37(m) when she stated that no relationship will form between us?

Some backstory, this girl started our whole “relationship” or “FWB” situation by stating “I just want you to know that I’m only using you to boost my confidence back up” which is a fair way to start something. No lead on, no games, just straight forward. She was recently out of a relationship and just needed a confidence boost. She called and FaceTimed a few times, we’ve spent some alone time together, and now it seems like every free moment she has she’s calling or FaceTiming me. Then after I picked on her when she was having a rough day and asked “do you need butt rubs?” And she said she was worried I was getting too comfortable with her and she was worried she was going to hurt me. I told her that she fully prepared me for the situation first thing and I’m good. Still, every free moment I’m getting phone calls, almost a total of 5 hours on the phone today. Anyone have any insight?

TL;DR: Girl was straight forward about being FWB but now spends what seems like every free moment she has calling me. Why?