Mother daughter relationship

I need some advice. My sister and i are visiting home this weekend for a wedding. We are staying at my mom's house. My sister and i ended up getting into an argument which in turn upset my mother. My mother started going on and on about how my little sister and i ruined the weekend (even though it was only Thursday). My older sister responded to my mom by telling her that the weekend was not over, and that we can still make it a good weekend. My mom was frustrated, so she told my older sister to "shut the f**k up!". My sister was really hurt by this because she wasnt even a part of the original argument. She told my mom is was rude of her to speak to her that way. My mom responded with "youre my daughter's and i can talk to you However i want"! Mind you I'm 31 and my older sister is 34. Do you think it's ok for a mother to speak like that to her adult children? Or do you think a mom should speak to her adult children with the same respect she would give another adult?