Is it reasonable for my roommate to....

My roommate asked me yesterday if I had any evening plans in the near future. I told her I was leaving the house to hangout with a coworker for the afternoon and dinner today. She asked when I was planning on coming home because she wants to have a dinner date at the house with her boyfriend (who lives alone next door). I said I don’t know , we are meeting up at 1pm sometime after dinner we haven’t decided on a end time. Then this morning she messaged me asking me again what time I’m going to be back tonight so she could make plans ... I still didn’t know (I generally don’t decide on exact end times when hanging out with someone) so I felt like I had to message my coworker to ask.

Is it a reasonable ask to want an exact time for me returning home? Asking again because my answer wasn’t exact? ( I actually didn’t know and originally gave a vague time early evening after dinner)