Whether you cut it or not, you might look into a great brush I found that works so nicelyon my daughter's curly, tangly hair - it is called the Hair Bean, it is one of those $9.99 "as seen on TV" things, I found it at the Dollar General Store, but it may be found at Walgreens or WalMart or CVS in the section with the as seen on TV items, or ordered online. I was skeptical at first, but it really does work great, and even on my daugher's BIG tangly hair, it gets all the way through and she doesn't fuss about the brushing like she did with traditional brushes.
I would say a bob would be cute...but the brush would help even with shorter hair!