Need social advice, what to do next basically?

So I recently had my haircut with this girl similar to my age etc she cut it a few times now and while having my haircut done, (I'm male) we talked about movies and I said I'll be seeing Deadpool 2 this week I haven't seen it yet etc, then at the end of the haircut she said to me that I'll have to let her know if it's good or not and she said if it's good she might have to go and see it herself. I took some time to think of the correct response and I said ok I'll let you know and said bye bye.

The thing is I really struggle with social stuff and reading between the lines if that's what it's called, common with aspergers. But why did she say that and what does it mean? I'm so confused because I don't understand how I'm meant to let her know? We don't even know eachother, we're just acquaintance's if that's what it's called, I don't have her contact info etc. Does she mean to let her know when I next see her in my haircut appointment or let her know before then somehow? I can't really walk into the hair place and say to her oh the movie is really good you should see it because it will just look weird right because I'm meant to go in for a purpose not to just go in to say that? Or am I overthinking it?

I'm not really a forthcoming person but I don't want her to think that I'm rude for not letting her know when I said I will? I am really not very good with this social stuff so if someone could explain it precisely the situation and what she means then I will know the next action to take, I kind of been put in a bit of a muddle because I don't know what the appropriate action to take next is now lol

She probably will cut my hair again so I don't want her to be sort of like disappointed if that's the correct word I don't know....