["I went shopping with my mom and sisters. My mom paid for my sisters' items but she did not pay for mine.", 'How come? Is your sister a minor and are you an adult?', 'My sisters are all adults, I am the middle child.', "That doesn't sound fair at all, I wonder why she did that.", 'I paid my bill and I felt so bad.']
If I were you, I would ask your mom why she paid for your sisters; items and not yours. That's so mean.
My mom and sisters went shopping. My mom paid for my sisters' clothing but she didn't pay for mine.