I'm getting my daughter into single track riding in northern VA. Single track and horse trails with dirt. Not a lot of rock gardens or high speed decent. She is outgrowing her trek 220 and I'm looking at a 27.5 bike for her in the $500 range. She is 4'11" and likely won't get much past 5'2". I'm looking at the diamondback lux 2 which seems to have a decent 6061 Al frame and reasonable components in sale for 499. It comes in 4 lb lighter than the trek that she rode and liked for a lower price. I also consider reaching up to something like a Cannondale cujo 3 for 699. I don't think about diamondback as high end bike maker, but didn't realize their reputation earned in bmx. Are their core bikes solid enough to build on? Are there other alternatives in that range?

Thanks