@Untang13d sorry to hear of your daughter’s health issues. With regard to planning and finding the right dog for your family, I would combine the advice from PollyRoulllson and dustofneptune. Massive post coming, because I am hopeless at being succinct! 
I also have a dc with health issues that have been extremely challenging (to the extent they have been unable to attend education for 5 years and at one point we were never out of A&E and had a care plan for rapid admission). I just wanted to offer an alternative view to people who think you can’t be in that situation and have a well cared for dog, as it can be hard for people to wrap their heads around if they’ve never been there.
If you’re anything like most parents of chronically ill dcs you will be exceptionally organised and will be really careful about fully researching and planning any changes to your family life - hence posting for advice. Several people in the support group for my dc’s condition have found getting a dog has really benefitted the whole family, particularly the mental health of the person that is ill and of the main carer, who gets a break and vital headspace while walking the dog. Our dogs have always been the glue that holds our family together, particularly during tough times and the amount of joy, love and laughter they bring into our home really is priceless and worth all the careful planning it has taken to have them as part of our family.
My situation is slightly different, as I have had dogs for over 30 years, so probably have more experience and find the puppy stage less daunting than some. I have had mostly rescue dogs, but we are planning on getting puppy, probably next year. For me this is easier to plan for and has enabled us to look into specific breed traits that suit our family circumstances. Many of my rescues, including pups I have had from a young age, have had issues caused by their poor start in life. I have had one purebred/pedigree in the past and it was lovely to have a pup I could raise from scratch, so-to-speak. She turned out to be an amazing dog and fitted our family perfectly and it was definitely the right choice for us at that point in our life. (I have since had more rescues.) This time we have chosen a breed that is very family orientated, doesn’t need excessive amounts of exercise, but will enjoy long walks, etc, when we can do them and is mostly a companion breed, rather than one that needs constant training and stimulation to keep them ‘busy’. It’s a breed that loves snuggling up with their people and from that perspective, I’m hoping they will be good company for my poorly dc, who is often bedridden. I would definitely say have a look at smaller, companion breeds, rather than anything from working lines or that needs a lot of mental/physical stimulation, as not only are they more likely to be content with more realistic amounts of exercise and training, they tend to be easier to arrange other people to care for in emergencies.
I would think about your lifestyle and how you would manage a pup. In our house there are five of us, all very used to caring for dogs, so there is always someone available for toilet trips/walks/dogsitting etc. We are used to being up through the night on nursing duties, so night time toilet trips don’t phase us at all. (We currently have a very elderly, poorly dog, so one of us always sleeps on the sofa and he regularly needs to go out in the night anyway.) On the odd occasion when no-one is around to cover us for an emergency A&E trip, we have back up people who live 10 minutes away and are willing to come round and sit with the dog/s for as long as we need. If we are looking at an overnight, we have a dogsitter who will stay in our home and if she is unavailable my PIL’s will come over and take the dogs to their house. We used to have a fantastic boarding kennels we had used for over 25 years and they would always take my dogs at short notice if there was an emergency, even going as far as to keep my two with their own dogs and take care of them that way when we had an emergency followed by hospital stay. Unfortunately the owner became ill and had to close down. My dogs have always been really sociable and we made sure that they adored all the people who might have to take care of them in an emergency, which makes things so much easier. Contingencies, back-up and back-ups for your back-ups are really important for peace of mind and consistency of care for your dog - but again, as the carer of a sick dc you are probably used to organising and juggling back-up care, especially if you have other dc.
Not sure if this applies to you, but it’s also worth thinking about safety, in terms of medication and medical equipment. You need to get everyone used to being really strict about medication, with storage being well away from a pup’s reach. We have a medication cupboard on the wall and daily medication is kept in locked dosette boxes well out of reach. Same goes for any equipment that has electric cables, such as bed-lifters etc, cable management and puppy proofing is something you will need to think about and plan for. Similar to if you had a mobile toddler in the house, only one with sharp teeth that likes to chew electric flex! If you can possibly fit one in, a totally secure puppy-proofed area or playpen is ideal for when you do have to take your eyes off them for a couple of minutes.
Be aware that finding the right dog may take some time. I started planning very early for our pup and have been in touch with the breeder for 18 months now. We won’t be getting our pup until we no longer have our old boy, as it wouldn’t be fair on him, but the breeder is aware of that situation and fully supportive. They don’t breed often, so we are also aware that we will probably have to wait, even once we are ready, but are happy to do so, because getting the right pup from the right breeder is so important.
Anyway, I have rambled on, as usual. I just wanted to offer a different perspective as someone who has a chronically ill dc and yet still manages to care for the needs of their dog/s as well. The puppy stage will be challenging, but in what way and how much depends very much on the groundwork, breed choice, breeder. It’s not always a complete nightmare and more people oriented companion breeds are generally a bit easier than some of the more energetic/brainy working types. So if you do your research, plan carefully and don’t rush into anything, it is perfectly doable and hopefully will bring as much joy to your family as our dogs do to ours.