I don't think girl crushes are always sexual. I have always been rather too fond of men, and lost my head over them, so I'm not given to Sapphic lusts, but I do so agree with OP about Serena Campbell. I would love to share a bottle of wine and some chocs with her and have a girly giggle - she's so twinkly and rather adorable.
Sexy? No. She invokes in me the same lovely warm cuddly feeling I get when I think of babies, not the swooping, soaring, visceral attraction I would feel for an attractive man.
Not that I feel that way much nowadays - blokes my age are, on the whole, rather awful, and I'm sure they feel the same about me as I've reached the age of 'oldbaggishness". 
I am not a messy person but...
Instant coffee….advice needed.
