About four months ago I was dating a girl I met through my university, we stopped and didn't see each other for a while and now she's texting me out of the blue.

When I first met her we went out together three times (real dates), I liked her and I felt like, even after all those dates, our feelings weren't yet shared with each other. So I planned to be frank with her on the 4th date and tell her I like her, put simply.
The 4th date never happened because she got sick, I guessed she wasn't interested in me, I went on a trip for a couple weeks.
I came back, asked her how's she was doing, if she was up for another meet, but she replied me with no subtext: "I'm not ready for a relationship".
Allright, I said no problem, we chatted for a bit and I spent the next months forgetting about her.

Now out of the blue she texted me "how are you?" and "I saw you in my dreams 2 days ago".
She's must be interested in me, but I can't deal with this right now, does she want me to text her back (this part I arleady did) and ask her out? I'm not a switch that can be turned on and off, I spent too much time focusing on forgetting her.

I guess I should ask her out because it's what I desire.

Maybe I'm misunderstanding the situation, help will be appreciated.