Like others have stated, it depends on the dog. I have two girls myself. My Newfie loves sex and will, not so subtly, ask for it if I go 3-4 days without making love. (She'll sniff my crotch intensely, pant, turn around and back her ass into me.) This is out of heat. In heat she's begging me for sex multiple times a day. My mutt mix on the other hand just plane hates sex as a whole. She wasn't even that interested in her last heat, the farthest I got with her was fingering. She tells me no, it means no. I'm not going to fight her on that. I love her and will respect her wishes.
But I ended up basically winning the lottery with my newfie girl, it seems most dogs aren't as crazy about sex as she is out of heat. But some will enjoy it if you do things right and take things at her own pace. Make sure you cuddle and pet her when you're done making love to get the oxytocin flowing. My girl and I usually cuddle for 20-40 minutes before I take her on a walk to pee. She's usually in a completely happy trans-like state. I make sure any sex is an act of love, and not just lust.