What time is it? Watches and horology

All depends on what you think she'll like. But more importantly, how deep your pockets are. I had exactly the same dilemma (first world problem) for my wife's birthday recently and got a good deal on a 90s 18k Datejust from a dealer exactly like your photo. Not exactly cheap but so nice and she loves it. Looks neat as a daily but can go with an evening dress and look gorgeous.

Other options:
Oyster Perp / Datejust can look good on leather strap and much less painful price:

Excellent, thanks for that. Don't mind spending a bit on this as I know she'll really appreciate once it's on. The first Rolex you posted is a good option.