Is fur appropriate?

My entire family and some friends are traveling to London the week before and the week following Christmas. This will be the first time for all of us to visit, and we’re all very excited! My mother would like to wear her (real) fur coat. I’ve been looking at photos of London street fashion, but I can’t tell if fur is appropriate or not. For instance, she can wear fur in NY all winter but wouldn’t think of ever wearing it to Colorado. Thoughts?