Really it's up to the couple ^^
But if they want to, then I say go ahead! I personally don't think it matters whether it's maleXfemale, femaleXfemale or maleXmale. If they want a child, they can do what they wish C: as long as they're prepared for the hard work that's needed for it, then there's nothing wrong.
Really, all a child needs is a safe environment and people to love them (as well as the obvious necessities ). If the couple supplies these to their child, then I feel that they're perfectly allowed C:
I could just be saying this, though, since I've always wanted to have children, and am sticking up for homosexuals :'D I guess we'll never know x)
But Bienie, are you trying to tell us something...?