I think whatever size you are there is a market and also confusion about what is what. When I started I was told to market myself as BBW and when I did blokes told me I was not big enough, I've also had big tit fans say my tits aren't big enough (40E!) because when they want big tits they want super huge ones, equally other guys have told me they are the biggest they have seen (I think they mean allowed to touch!)
The thing is to market yourself to show off the bits you like best and the bits that get mentioned by clients- even if it's a bit you don't much like about yourself if several men rave about say your bum then you should probably talk about that in profiles and show pictures of it. I think (loathed as I am to say it) client feedback on these things is worth listening to if it's said more than once or twice.
I always maintain being honest about sizing is the best way to go, but even then there will always be someone who says You're not a size X or Y. You just have to get used to that and if you are honest it shouldn't happen often.
I have the big tits and tummy but no bum so when men ask if I have a big bum I'm honest, OK I might lose a few bookings but I'd rather that than them walk out or be narked with me.
I think you have to get out of your head there is a 'typical' escort, there isn't. You might think so looking at agency photos, but look at independent women- there is every shape and size imaginable out there and I think if you come across well on your profile and come across as decent and honest that will go a long way. I think many men actually often want a woman who is reliable, clean, interesting and kind and does the services she says she does. And to be honest, those are the clients you want- the ones who are going to get riled over whether you are a size 14 or 16 are more likely to be awkward entitled arses!
As for the OP, talk about your lovely legs and pert b cup boobs and just don't mention the bum or tum! I would also avoid mentioning BBW too- I think you're probably too small for men who search BBW.