"Witches who are born witches tend to have the greatest power." As evidenced by Rowena and those in the great covens. Witches who were weaker in power or who learned their magic without being born to it typically didn't join a coven.

"Whilst magic can be learned, those who are not born to it usually can hold less power."

She says it very casually, even if Rowena is in the first camp. A witch born with her magic, with that potential.

"I honestly haven't thought much about how other species breed."