Lots of doctors like trazodone for sleep, because of the dual effect and because it's not a controlled substance that invites DEA scrutiny in the US. That said, it's kinda known to cause some next-day grogginess/mental slowing. I've never been a big fan of sleep drugs that have a really long half-life, or that have active metabolites (compounds formed by the drug as it's transformed for excretion that have effects of their own).
If your mom has a history of migraine, trazodone is especially good at making people feel headachey after, due to a particular metabolite.
The preferred agent for sleep in LBD seems to be Klonopin (clonazepam). There's information on its use in LBD patients around page 18 of the document found at:
I think it's worth discussing with her doctor; there's no sense in sleeping well if it doesn't leave you refreshed and perky the next day.