Were there any better options to replace Claudia Wells than Elisabeth Shue?
The main criticism that I've heard about Shue is that she's quite hammy and annoying as Jennifer, which was completely inconsistent with the way that Claudia Wells portrayed her in the first movie. Plus (and maybe this isn't entirely fair), Shue looked a tad bit too old to be plausible as a teenager. In fairness, she's only about two years younger than Michael J. Fox is in real life. And it wasn't that long ago that she played a teenage girl in Adventures in Babysitting, despite already being in her early 20s.
https://www.reddit.com/r/BacktotheFuture/comments/gtopx2/who_wouldve_been_a_better_replacement_jennifer/