I was on depakote for a long time (7 or 8 years?). It worked really well for me although I still needed a combination of lithium, an AD, an AP and a benzo (but I'm very hard to medicate). Weight gain wasn't bad until high doses that they are very unlikely to use with a geriatric patient. It did make me tired all the time but with the combination I was taking and the high dose of depakote I wouldn't have expected otherwise. It does work pretty fast; I think about 4 days to start seeing an effect. They do have to monitor the level with blood work.

I hope she is feeling better soon.