My wife is the same measurements. She rides a 141 Burton Lux. Here's the thing, I'm going to give you a general range to look at, but you should consult the specific board's spec sheet. It's a good idea to look for a size where her weight falls in the middle of that weight range for all-purpose. My wife is on the low end of her board's weight range, but she doesn't mind because she likes the playfulness of that size more.
Each board, even within the same brand, will have different weight ranges for a given length. For example, a 141 Burton Lux will support a different weight range than a 141 Burton Feelgood (this is just an example, I have not looked to see if it is actually a fact for these two specific models).
Also remember to look at the boot size accommodations of each board. You don't want to put her on a board that supports her weight, but is too wide or narrow for her feet.
I'll also give you a basic rundown on board flex:
Soft - Medium - Stiff
Freestyle - All-Mountain - Big Mountain Freeride/Powder/Carving
Playful - Versatile - Stable and Fast
The above are respectively.
That is a very basic rundown. Boards nowadays have a lot of tech in them so these lines get blurred. For example, a Turbo Dream is mid-stiff, but has dampening Harshmellow tech which makes it ride stiffer.