The first this is you have asked about ball pythons on a venue dedicated to them. You are not likely to get apposing view points.

Snakes in general are low maintenance spot checks daily, fresh water periodically (debated here, personally every two days mine get fresh water) and then feedings weekly or so, and every month or two a big cleaning. Snakes are not social animals so not having time to bring them out and spend time with them is not neglect. It is more for the keeper than the animal.

The sound is a odd issue snakes have an ear but not like we understand they have no tympanum. They 'feel' sound with the jaw. This is actually very sensitive to small amounts of vibration. So yes some provision for the drums maybe needed not so much from air borne sound (pressure waves) but from transferred vibrations of the enclosure. Some kind of mounting system that isolates the vibration of the stand to enclosure might be a sensible addition. It is also likely the snake will adapt to the sound and have no issues. Herd to predict.

In an attempt to be fair lets speak of some of the downsides.

IMO a 4 year old cannot be left unsupervised with the snake this is mostly for the health of the animal not child. A snake placed on the floor will often race to the least accessible darkest hardest to reach corner. They need supervision at all times, The 4 years olds I know don't have long attention spans.

Salmonella there is a chance for all reptiles to be carriers, and that is increased in that a snake may crawl through deficit and carry salmonella on the scales mouth to scale contact could be bad. Personally I am not crazy cautious about it, just general cleanliness is all I ever do. It is a bad idea to pet any animal and eat a sandwich dogs also can carry salmonella. It should be mentioned as this may weigh in on a decision.

The enclosure and heating system. Ball pythons are native of africa, they need environmental conditions to be african. This means technical tinkering when the enclosure is set up. Heaters, thermostats, and bowls and such all need to be in balance. This is likely to be an animal set up to be viewed so figure that you are going to need 400-1000$ to get all the parts for this. Yes it can be done for less, but a display enclosure properly set up 400$ is not a lot.

Stigma, there is a stereo type that goes along with keeping snakes. It is often wrong and not correct at all, but it still exists. When people discover you have a pet snake there is a response and sometimes that response is negative and can change the relationship between the people involved. You mentioned you have joint custody, it is something you should be cautious of that the other parent may use the snake against you.

Life span, a ball python isn't a dog. It is common for them to reach 20 years old and the maximum life span is undetermined at this point. The oldest recorded was over 40 years BUT that only means that animal was in captivity for 40+ years. It was an adult when it arrived. It is possible your daughter could be close to 50 when the snake dies. This is something you should not take lightly.