My cousin asked my girlfriend if she's unemployed at breakfast

We went to a breakfast organized by my family over the weekend with my girlfriend. Everything was quite calm, and the food was being enjoyed, you know. Then, my cousin suddenly turned to my girlfriend and asked, ‘Are you still unemployed?’ My girlfriend initially played it cool, but then her expression changed, and she really lost her mood. I was so embarrassed… Should I set boundaries with my family, or is my girlfriend misunderstanding? Do you think it’s normal for them to take it so personally?