My mom has low blood pressure. is there anything she can eat to help her? anything natural?

Raise BP: One can raise his BP by ingesting more sodium chloride(salt) or by eating or drinking more caffeine containing foods(chocolate) or liquids(coffee). However, since i don't know your mom's medical condition, i wouldn't institute such measures without her physician's advice.

Depends on cause: Does she have symptoms? If dizziness isn't a problem, then she may not need anything. Otherwise, increasing fluid and salt intake will usually drive up a person's bp--that's why we try to limit salt for people with the more common problem of high bp. Usually not hard to increase your salt intake, but she should definitely discuss with her md to make sure there are no concerns with this approach.