Gwenllian verch Hywel - Dates of birth and death

Catrin verch Gruffudd - her DOB c 1240 is after the DOD of 1235 of her father. Not much difference but when combined with the question below I thought I mention it.

Elen ferch Gruffydd - her DOB of c 1089 is prior to the DOB of her parents of c 1195 and c 1205..

I realize that the dates are a general idea but wanted to check if there was any additional information that might be available.

Thanks,
John Love