What are the complications of adopting a child? Are they overridden by the need to contribute to someones life and save him or her from a precarious situation?

Shalom U'verachah, It is a great Mitzvah to adopt a Jewish child who is homeless and without parents. There are questions related such as the prohibition of yichud, i.e. seclusion of members of the opposite sex, and the solution to this depends on the age at which the child was adopted. There are other ways of solving this situation. Today many couples adopt non-Jewish children and convert them, this obviously carries with it other relevant halachic questions related to the conversion process itself. In all cases a Rav should be consulted who can guide the couple through the process of adoption and conversion if neccessary. Kol Tuv