Board Thread:General Discussion/@comment-27760482-20160208184840/@comment-4010415-20160212204702

Guyver92 wrote: for all we know it could have been a few years that she raised yang as a single mom before raven became a maiden or became a crazy woman. "He wouldn't tell me everything, but I learned that the two of them had been on a team together with Summer and Qrow, and that she'd left me with him right after I was born. No one had seen her since." - Yang, in Burning the Candle

In other words: Immediately after giving birth to Yang, Raven left Yang with Taiyang and disappeared.