My wife who is 5' on a really good day
uses a step through bike. We were shopping for her last year and she didn't like the bike where she had to throw a leg over a bar. Found a nice Bianchi "grandma" bike my son calls it. The bike was really nice but no go on the bar. We did find a bike called Roll from Spec. It was a big winner for my wife because it was step through bike. She loves it and rides it often now.
The bike she chose:
Roll - Low-Entry | Specialized.com
The bike that was close second. But the step through wasn't quite right but still an awesome bike. I really liked them both but this was a really classic bike.
Venezia Lady - Nexus 3sp - Bianchi Bicycles