British article on co-parenting by friends (or by people who meet on websites designed to match co-parents) ignores legal issues

The British newspaper, The Telegraph, recently ran a story about people not in intimate relationships choosing to parent together. The lead family started as a single lesbian and a gay man chatting on an online fertility forum and is now a lesbian couple and a gay man. The coparents are not all gay. The article links to three different websites where people looking for such a co-parenting