yvonne answered question 6/4/2010 My Puppy Is A German Shepherd Husky Mix, And Was The Runt Of The Litter. She Is Now 4 Months Old And Weighs 20 Pounds, How Much Bigger Will She Get? She will stop growing at 1 1/2 but will start breeding at 6 months old, Spay her now!!! Don't put the poor baby thru having babies.