My hairless rat has just 1 baby and shes real territorial ,,i just need a lil advice?

bought only 1 female rat and i look in her cage 2 play woith her like i do every night b4 i go to sleep and she has 1 lil itty bitty pink baby,,,idk wat 2 do ,,like how long until i can play with it and hold it like i do the 1 i already have,,,,and also she lunged at my finger and idk if she tryed 2 bite it or not i mean she real moody so im just wonder will that affect her behavior towrds me in the long run???,,o and if her 1 baby is a male will they try to breed even tho theyre mom and son???