Yikes.
IIRC Gwladus verch Gruffydd was a sister of Rhys ap Gruffydd, Ystedur verch Caradog was his wife/mistress (the distinction isn't always clear due to liberal Welsh divorce laws and casual attitude toward polygamy), and Gwenllian ferch Madog was definitely his wife.
Just how messed up *is* this?
Moved the information for Gwenllian ferch Madog over *to* Gwenllian verch Madog
Now, how about sorting out the rest of the mess?