No it's not too late. But she is not a dog, she doesn't need to be trained lol.
Do you co sleep? I take it that's an issue? Why not get a twin bed instead of a crib... my daughter hated the mattresses and wouldn't sleep on it to save her life. She coslept for 19 months, then had a bed in our room, then has her own room. It just took a steady routine, some night wakings, and a lot of comfort and she now sleeps really well on her own. :)
Also, try the No Cry Sleep Solution for Toddlers by Elisabeth Pantley. Be sure to get the toddler version, as she also has regular one for babies. It is a great book and will answer many questions. And, most importantly, WILL help your toddler to sleep/sleep on her own if you follow it correctly.
Does she sleep through the night?
And i agree, no need to train her, she's not a dog :)