If they are registered then find a registered online forum and offer for sale... advertise locally or on something like facebook marketplace... Or as suggested, send to the local auction/salebarn/stockyards... Some of them have a monthly breeding/bred cow sale and they could be sold that way...
Right now the cows are worth $1.00 to $1.50 for cull cow price... calves are bringing in the $2.50 to $3.50 per pound for a 4-600 lb steer... little less for a heifer...
Sold as a bred they might do better, or cow with calf by side... BUT....They are splitting many cow calf pairs here with the fatter cows going to slaughter at the $1.00 lb or more price... so say a 1500 lb cow is worth $1500 and her small calf is worth anywhere from $300 to 900 a head... as much or more than she would bring as a cow/calf pair some places...