My mom only wears nude pinks and sheers, so I've posted up a couple of colors I own that I think would suit her:
Allegoria isn't a bad color (albeit boring), but is a major pain to apply. This is one of the streakiest polishes I have ever encountered. I have on Barielle Camouflage underneath to help balance this out along with four coats of polish. It is currently part of Chanel's Celestial Lights collection. The price isn't justified, so move on to the queen of these colors: Essie.
I bought Mademoiselle after seeing The Polish Addict's great French manicure tips. It's a sheer jelly pink. Mademoiselle might be streaky, but it's not quite as bad as Allegoria. A base coat of Camouflage will help out greatly. However, Allegoria is more opaque and is probably better for "regular" use, but Mademoiselle is perfect for French manicures.
Even if you don't wear basic colors like these, I wish a happy Mother's Day to my mom, your mom (no pun intended, lol), and all moms everywhere!