Coping with 2 kids

Hi mummies. My 1st is 16m and am delivering my 2nd in oct. Just wondering how do u handle 2 kids esp during sleeping time. My 1st born does not sleep thru the night. She still wake up ard 1 to 2 times for milk. However my concern is, if newborn is in the same room, will my 1st born be sleep deprived? #pleasehelp