My initial thought was 'okay', but then I started thinking a little more and came up with an even better idea.
Why not just have a third movie?
The original came out in 1987. I fondly remember it because it is the movie my father took a friend and I to see on my birthday. My mother took my sister and I to see the sequel - Three Men and a Little Lady - in the cinema when it came out over here in the UK in the early 1990's.
A third film could see the three original men - Ted Danson, Tom Selleck and Steve Guttenberg - reprise their original roles and find themselves having to deal with some sort of catastrophe a grown up Mary puts them in (marriage, her own pregnancy?).
I'd much rather revisit the people from the 1987 and 1990 movies than start all over again.
According to the articles I've read, Zac Efron has signed up for the project. It still needs a director. Once its complete, it will air on Disney Plus.