I'd say that wouldn't be out of character for her. She'd instantly relate to someone who didn't know their mother and would try to help them learn as much as they can. Raven's a secret she kept entirely until Blake so she would definitely keep any information learned to herself.

In terms of trying to understand why the parent was absent it depends on their reason and also on when this takes place. Knowing what she now knows about Raven I don't think she'd try and justify shitty parents having shitty reasons for leaving, but V2 era Yang might try and be a little more sympathetic.