Sister question

Hi everyone this is my first time posting so please bear with me.

I have recently found out I am pregnant with a little boy after losing my son 4 years ago and having 3 other pregnancy’s that 1 I lost 2 was a moler pregnancy and the 3rd I had to abort due to the baby having the same genetic disorder as my first son and the baby would have suffered and died if born.

Anyway I told only close family till I found out if baby was ok since then my little sister has been quite mean to me telling me I was stupid for falling pregnant again even though I was on the pill and have been with my partner for almost 10 year and she even asked me why I needed a new pram when my family all chipped in for one before baring in mind it was almost 7 years ago and was a double buggy when my 2 girls were little and when I told her tonight that if I pass my course this year at college I will be able to jump forward and do my BA with honours and she called me a liar and said that my college is on crack and that I am stupid for believing my advisor!! She was really mean!

So my question is ... is she jealous or am I just being over sensitive??

She is 4 years younger than me with no kids except her dog and has been with her partner for 6 years. We have always been close till she started acting abit out of sorts.

Thanks for any help x