Shouldn't be discouraged unless it can be shown that having two same sex parents is qualitatively worse than having none, but it has been shown that having a mother and father is better for the wellbeing of the child which should be paramount in cases of them being wards of the state.

Still, they shouldn't be precluded from adoption especially as there really aren't enough couples open to adoption to go around. Of course any such regulations shouldn't apply to private adoptions.