I have girl crushes like you're speaking of, and crushes on girls. It has slipped out in convo and many people I've met just give me a quick double take before carrying on
I'm bisexual and not ott with it, but if we're discussing hot people I'm happy to comment either way!
Girl crushes for me would be Pink, and a few others I can't think of right now but people who I feel can be looked up too or are a good influence.
Crushes on girls: Kate Beckinsale, Taylor Swift and Hayley Williams. Thay're the three I have liked for years, the latter two being a similar age to me.
My best friend thinks it's awesome, he's always loved that we can discuss girls together and is quite happy to pander my girly-ness of discussing men and will agree/disgree when they don't conform to the male version of girl crushes 
kreecher: I agree with Dawn French! She's brilliant :)
I frequently comment that if only I were 30 years older, male and gay that I would find Stephen Fry perfect for the same reasons you like Dawn Fench lol tbh though, if I could have Stephen Fry come over for tea one day I'd probably faint before he walked through the door 
OP I like Jennifer Love Hewitt too, there's an innocent look about her.