am i right?

hi all over the last few years i have been breeding yorkies with my mum, its nothing big time but we share the profits of each pup we sell we always go half, now earlier this year a litter of pups were born at my mums house the dog killed them very sad of course, my litter of pups 5 in all were sold last week i gave mum her share, anywayz mums pet yorkie got pregnant by mistake, she had her pups which were sold on and mum has not divided the money because this was her pet dog, i have passed on the proceeds of 8 pups so far this year and have recieved only the proceeds of 2 from her, we always agreed that any monies made would be divided, i feel so angry but how do i get over this subject with her . i feel let down and frankly out of pocket am i wrong? because technically mum has not lost out atall with the loss of the 4 pups because she has kept a full litters money were as i have had half shares of one litter does this make sense to you??