No she doesn't have a ridge, nor did any of the others in the litter that I saw (I adopted her from a rescue when she was 7.5wks old), but not all ridgeback crosses have the ridge. I've met full ridgebacks without it.
A lot of people have asked me if she has shepherd in her, I think because of her colour, but ridgebacks also come in that colour and I don't see any shepherd traits in her body type so I don't know... either way she could easily be shepherd cross, I know absolutely nothing about her dad except that she has to have got her size from him because her mum was apparently huge. (which is why I think mum was mastiff/ridgeback, because mastiff/ridgebacks are enormous)
I do wonder if she has some staffy in her, because she trills and talks like a staffy, but mastiffs also have a lot of trill and growl so it could have come from there... she's not really solid enough to have much staffy blood in her, especially if she has mastiff as well. She's very elegant.
Aaaand just because she's cute;
Sorry about the size! They're uploaded on FB, I didn't think they were so big :/