For sure you would need more advice. For a physical limitation make sure you are equipped to be able to lift/carry the child longer than you normally would. The child may become 30 pounds and still be unable to climb stairs or not be toilet trained and need to be changed at 4 years old. My daughter didn't pull to a stand till she was 4 years old, started cruising at age 5 and took her first real steps at age 6 - that was a lot of lifting and carrying and my back and knees have paid for it but there wasn't really much else we could do. From that standpoint it would be for such a short time you likely wouldn't suffer any lasting effects if you lift and turn carefully. Brianne is now 20 years old and I am over 50 so my age is part of the sore back and knees as much as she is.

For the food aversions it is likely to certain textures so you may find you are feeding the child puree food instead of table foods and being careful when mashing a food such as a banana that the chunks are only a certain size. If the parents will provide for at least the first little while till you get comfortable with what child can eat that helps a lot. For Brianne she has trouble chewing and swallowing so everything must be mashed (ie like it has been pre-chewed as gross as that sounds - a magic bullet is your best friend) and everything must be very moist - we add applesauce or yogurt to the top of all her meals making sure that the yogurt on the tip of the spoon is the first taste she gets and that sort of gets spread over the top of the spoonful of food as she puts it in her mouth or should I say we put it in her mouth as her hand eye coordination is poor so just easier to feed her, watch for wrong size lumps as I go etc.