Her accent was non-existent, but for me, it's mostly just that Melanie Griffith is WAY too old to still be employing her whole "giggly, flirty, little-girl voice" approach to acting. It was painful to watch, and it made it look like she was flirting with every male she had a scene with - including the one playing her son. If her character was supposed to be some cougar on the prowl, it would've been one thing, but I don't think that's what they were going for. Her outfits didn't help either, most which looked meant for someone 20 years younger. She just didn't come across as motherly at all - and for some reason I really imagined Danny having a tough, no-nonsense east coast style mother, not some giggly, silly person.
Apparently, I REALLY didn't like the casting, lol.