You're still in the 2-week window, and so could still come down with the virus. (I think that lately they've shortened that window to 12 days, but no medical expert I've seen quoted has said "most people" will have shown symptoms by day 6.)
You don't mention if you and your mother were masked. If your contact was in the car for 1 1/2 hours and neither of you wore a mask, and you were side by side, and presumably were talking, it sounds like you had plenty of chances to get the virus.
There is some research that says about 40% of people in the same household as a person who got Covid, also got Covid. That seems to leave 60% who didn't get the virus. However, the research didn't say if it had to do with the type of contact in the house, or if some people are less likely to catch it than others. I assume you are quarantining from your husband, if he has to go to work?
Good luck, keep watching your symptoms and keep testing.