Misunderstood.. I guess!

Am I too straight? The word from my mouth are too poison?
Today I told my mum about something and im realise that she dont have good patient, easily to get angry! Me and my family have a dinner together, when on the way fetching my sis at her friend's house my mum was keep on complaining that her daughter never love to stay home.. As I know is my sis went her friend house is because her friend flying to US soon so its take a very longer time to meet each other. My mum is think short person and she never think about people feeling beside her own. Anyway, when reach the house my sis come out from the house late bit so let us waiting and I know sure get mumbling by my mum.. When she start mumbling we ask her be patient and I spoke out a word with my sis that if mum no mumbling her mouth will itchy! This is just a joke but my mum heard and she angry at me.. She angry until dinner done.. feel speechless and feel she really sensitive recently! Mayb she kept herself too long at home..
Trying to bring her out and she lazy not feeling want to go out.. so the end also stay at home and I just bring my sis out! Thats it.. Want to share with somebody but no one too so throw my feeling on here better! Unhappy but also feeling nothing! Good Night =/