Hiya! I'm in a similar situation, actually. I'm 32, single (for two more weeks), childless but not dogless, and I've been here for two years finishing my bachelor's degree.
I started out studying English and Drama together, but switched to Drama when I realised the culture of education in English wasn't for me. It was especially disappointing because I had always got on so well with HE English in the states.
I recommend strongly that you ask lots of questions about the university's history with mature students. Consider the grading culture, it's incredibly different (and I've found it hugely frustrating): 100% is only a mark only God could get, the scale is based on all human capability, rather than the course expectations. Consider the differences in British and American literary criticism, you will have to adapt to the UK style/state of mind. Ask if your department contact is willing to share some of their recent top marked assessments for you to look at. Consider that UK instutions are obsessed with objectivity; deadlines are hard and fast, all work is submitted anonymously and often marked by a second marker who is external if it's an exam, and much assessment is done in controlled environments such as exam halls where you write your essays within a time limit.
Some days, I wish I went to uni for a science degree, to be honest, and I know the above sounds gloomy, but I wouldn't change my choices for the world. Going to uni for English, as an American, is tough, but there's a lot more you gain for it than the degree (which is no more valuable than a US MA in English).