The majority of households who work full time and own dogs have no issues leaving their dogs crated or free roaming (if they're ready) for 8-9 hours a day. At 4 months old, your pup probably can't hold it that long. I would guess 4-5 hours at her age, so a lunchtime potty break would be great. Many people also use a play pen attached to the crate, and the play pen has potty pads put down so the dog can use the crate for sleeping and the pen for potty, but thats only a temporary solution until the dog can control their bladder.
I like to leave my dog with a long-lasting treat like a frozen stuffed Kong. I stuff it with wet dog food and a tiny bit of peanut butter to "plug" the ends.
I like to leave my dog with a long-lasting treat like a frozen stuffed Kong. I stuff it with wet dog food and a tiny bit of peanut butter to "plug" the ends.