" She wants to go somewhere in February, but insists that it must be warm. "
it's not like she's a wife, where you can swap them out for something better. this is your Mom, and you sort of have to make allowance for that.
is it possible to find a awesome coast hike, with perhaps a town and motel at each end ? that way, she'd be getting warm showers at least, and not have to cook (mine retained a burning pathalogical need to cook right up until the final hours). you could load her up with a very light pack containing her clothing and kit, and you can carry just everything else.
i have no idea the condition of your Mom. mine made it up (and back down too ! ) Mt Diablo in reasonable time when she was in her mid 40's, and section hiked across the state of California at the age of 67. (tales of this trek relate many sandwiches eaten along the road, and an respectable consumption of wine downed with hiking and life friends Paul and Helen.)
they did not camp outside in any way. but wandered backroads and small towns west to east.
that is my suggestion. a few towns, warm showers, and lots of wine.
take good care of her. if you've got a decent one (rare in this day and age), they're the best thing ever walked the earth.
good luck ! (because even Great Mom's can sometimes be a pita),