I am not sure that I understand the question, but I'll take a go at it.
As others said before, the word padre can never be used specifically for a female; you would use madre. The plural, padres, would include male and female, but padre, does not. This is consistent with the DRAE definition; the plural includes both sexes, but the singular does not.
There is a word that can be used for any parent: progenitor. This word can vary to progenitora for a female parent, but the masculine progenitor can refer to either a man or a woman. Currently, official documents in Spain no longer read padre and madre for a person, but progenitor A and progenitor B; this makes no assumption as to the sex of both parents. But progenitor is a fairly formal word.
Whenever you mean any parent, you may also say el padre o la madre. Similar to what Santiago Tórtora says for Argentina, in Spain the formula padre, madre o tutor legal is quite usual to mean any child guardian.
I would say that the use of the word padre, in singular, to refer only to a man and never a woman is not controversial among Spanish speakers, unlike what happens with many other masculine words.