Has anyone actually SEEN Bette Midler lately? Even in close-ups on TV, she looks pretty great and can easily pass for 60 or even late 50s. Maybe Streisand could give her a call and see who does Midler's make-up. (Not that Streisand doesn't look good for her age, but she still looks her age.)
While we're at it, let's correct the OP's assertion that Dolly its "semi-wealthy". Why does he thinks she performs all the odd jobs she does? Why does she sell herself so aggressively in the opening number (either opening number: stage or screen)? None of the odd jobs on her greeting cards is high paying.
Dolly Levi is a formerly wealthy woman who has spent the last umpteen years getting by as best she can. THAT's why she hasn't been to the Harmonia Gardens for so long. It wasn't in her budget.
In fact, that's why she is marrying Horace Vandergelder. Oh, she likes him well enough and knows he is manageable, but there's nothing in the play to suggest theirs is some great passion, especially not on her part. In speaking to her dead husband, Dolly actually says she wants to get married because she is tired. (This is just one reason some people objected to a film Dolly in her late 20s. Speaking of the film and though she sings "Love is Only Love", it's clear she's talking about a kind of love without fireworks.)