family

so I have two kids with my current husband... our first is 2 years old our second is 9 months old... both girls...anyways I've noticed his family has treated the girls different mainly his mom... she will go out of her way to buy clothes, toys, and food for the older one but nothing for the baby... it's not an age thing either because when our first was this age she spoiled her rotten... everything is always .... this and .... that.... the thing is our 2yr old looks just like him whereas the baby looks nothing like us... she is white with blonde hair and colored eyes... she looks very similar to my 4 year old who has a different bio dad...just to prove my point I'm willing to take a DNA test to prove my 9 month old is my husband's and that I didn't cheat... I mean it's the only thing I can think of as to why his family treats them differently... and then don't get me started on my husband... letting his ex gf borrow money to pay her damn rent that's late and mainly cuz of his boys... ugh treats them soo thing