I'm confused....

I am totally confused. That may not be news to some of you... but this particular confusion is regarding setting up a playdate for my daughter with her bff. It shouldn't be a big deal, right? In an earlier post, I noted how we had been canceled on for a playdate two times. I decided to give up. The mom had arranged play dates and then cancelled at the last minute each time. Sucks for the kids, because each time I drop my daughter off at school, her bff says, why can't I play at Amanda's house, or why can't Amanda play at my house? I don't know, go ask your mom!
Anyway, the mom had been working part time at the beginning of the year. Then, about two weeks ago I noticed her daughter had switched to 5 days a week at school, like my daughter. I figured the mom was working full time again. Cool.
But then last week, there was a cute card in Amanda's cubby. It was decorated by the bff and a note was written by an adult. "Hi Amanda, I want you to come play at my house soon. Love, bff."
Shit... I lost the mom's phone number because I didn't figure I would need it. But I did have her email address from when i was a room parent last year. I emailed her. The response I got was confusing.
Something like, "Oh, the problem is I'm working full-time now. But maybe we'll see you at the park for the preschool get-together." What? Why would you send a note basically inviting my daughter over if that wasn't what you intended? You work full-time. That's so cool. I work as well and understand that. But I wouldn't have my child invite another child over while knowing that it wasn't possible for them to come over. Make sense??