The timing would work out incredibly well. Spider-Man 3 was 2007. If Peter and MJ had Mayday in, say, 2009, they could make a Spider-Girl movie in 2024 and have her as a sophomore in high school.
If Lynda Carter can cameo in Wonder Woman 1984, there's no reason Nicholas Hammond couldn't cameo here. It's weird that many superhero actors from the 1970's are still so well spoken of (Christopher Reeve and Lou Ferrigno as well), but Hammond doesn't nearly get that kind of respect.
First time we saw multiple Spider-Men from other realities meet, I believe, was on that cartoon.