Medlands explains that Emmeline’s parentage is uncertain.
Here’s the link: I’ll put it in the profile, too.
https://fmg.ac/Projects/MedLands/enguntlo.htm#WalterLacydied1085A
Although he does say it is speculative, Cawley does present the case that Emmeline could be the daughter of Drew de Baladon:
https://fmg.ac/Projects/MedLands/WALES.htm#EmmelineMArnoulHesdin