Since I big and pregnant now and in the third trimester, it varies. Sometimes I am horny and can do it 2-3 times/day. Sometimes I just like to lay in bed and cuddle with the hubby and get feet/back rubs. Also…pregnancy sex has been different for me…ummmm…lets just the increased blood flow down there=oooohh weeee! 
So right now I am good with 4-5 times per week. Before pregnancy it was almost every day. But there’d be weeks when we get in like 3 quickies during the week and then make up for it over the weekends and when the child goes away on sleepovers.
Multiple times a day would be awesome. However, even with a willing partner real life schedules and stamina would probably get in the way. If I’m voting for my brain, I’d say multiple times a day. If I’m voting for my body, probably once a day. If I’m voting for my schedule, probably 1-3 times per week.
It’s not a simple question to say the least.
Right now, pregnant and second trimester, I’d like it a couple few times a day. Before I was preg. I varied between wanting sex a few times a week to ‘don’t touch me’ depending on where I was in my menstrual cycle. (default is the more the better though, which I don’t get because my husband works long hours and gets tired. yay for toys!)