I do that all the time, but it's warm hawaiian rain usually and I'm far far from family, actually my mom never really cared if i did this as a kid either now that i think of it.
I am guessing your mom is a bit overprotective, probably doesnt want you to catch a cold or get dirty. 🤔🤷🏻♀️ I'm sure she means well tho.
I think it's totally worth the release the rain can give in that way, a quick load of laundry wash and dryer later is the only price I've had to pay for getting soaking wet while say crying in the rain or standing and thinking or even dancing in it. I in particular I love rain 24 7, so I of course support it, but yeah don't upset your mom hehe.
The shower is the next best thing eh...close eyes and imagine being outside with the rain pouring down over you cleansing away whatever you want it to take. 🤗💕🌧☔️
anime portrait of a male person with black hair and closed eyes, wearing glasses, light beige dress shirt, and light beige jacket, facing up, standing in a rain, simple beige background