Do you think this age gap is okay in a relationship?

I (m25) recently started seeing a girl that is 21. She’s a college senior and I graduated 2 years ago. But she’s very pretty, mature and fun. I have been reliving a lot of the fun days I had as a guy in my early 20’s and it’s been like a shot of youth. But also Ik this is cliche but she is very intelligent for her age like 21 year old me wouldn’t be able to date her. We are just having a lot of fun and have been seeing each other for near a month now. I’ve had friends say “u realize when we were seniors in high school she was in 8th grade” which is weird but I don’t think a 4 year age gap is the worst thing ever. Thoughts?