Nikon D70s: today's equivalent?

Hi - I am looking to upgrade my wife's nikon D70s for Christmas. She has had it for years with an 18-70 lens and shoots some fantastic photos. she is an enthusiastic amateur, a bit lapsed since kids but still keen.

My question: what is the equivalent camera in today's nikon range to the D70s? I guess it might be the d7000 (only logic being they both start with 7!) but it definitely wasn't that expensive (and I wasn't looking to spend that much). The D5100 sounds fantastic from the reviews and I am really tempted, but don't want to find it is worse than what she has (although cameras seem to have moved forward so much I guess that's unlikely)!

Any help really appreciated,

Cheers