Potty training with full time job

My aunt has a puppy about 14 weeks old. She works a full time job with a slightly irregular schedule (house cleaning, some days off, some days early). Because of this, she’s found it difficult to enforce a crate routine, or much of a routine at all when she’s gone throughout the day. Along with this, she hasn’t been able to properly potty train the puppy.

I have my own puppy, her sibling. I’ve had a very flexible schedule and because of that, have been able to crate train, potty train and maintain a routine. So I have some experience but have no idea on what kind of advice or help to offer when the puppy is frequently free roaming within an enclosed space during some hours of the day.

How should my aunt go about potty training? I assume she should stick to enforcing after she gets home from work. Honestly I don’t even remember how I taught my puppy.