I'm not a experience breeder, I've just bred my Rubi (Rubie's namesake

) three times but I don't think it's possible to feel the puppies until she's put on a lot of weight and she's nearing labour. You say she's getting wider on her back, couldn't she just be getting a little fatter because she's perhaps overeating, not getting enough exercise or simply due to her age?
Like almost everybody said I do believe ten is too old to have puppies, even more so if she's a first time mom.
Please keep posting and let us know how everything is getting on. I wish you luck.
Rubi

, Jennie

and pussy cat Mimosin