Mom is upset he hasn’t proposed

I’ve been dating my partner for 2 1/2 years. My mom got proposed to after 6, when she was my age. Which is understandable to assume, if we weren’t STILL IN HIGHSCHOOL. WE ARE JUNIORS. HE DOESNT TURN 17 UNTIL JUNE. I TURN 18 TWO MONTHS LATER. WHY IS SHE MAD??? I DONT EVEN KNOW IF I WANT TO EVEN G E T MARRIED AT ALL. I HAVENT EVEN GONE TO MY FIRST PROM WTF???

Edit: she doesn’t want me to be married, She’ll kill me if I get married before 20. She just wants me to be engaged until then(also like her)