Honestly I feel this guilt whenever my baby is sick and the first few illnesses I tried to keep giving healthy meals and she ended up not eating at all. Now I see that it's better to just give them stuff they like so they're getting some nutrients even if its a bit high in sugar! It won't last forever.
Once they’ve reached a year they are able to eat more sugar and salt so don’t worry
My husbands a doctor and he always tells his patients to give whatever they will take when they are unwell especially anything that can increase their fluids intake like popsicles! Don’t feel guilty, it’s better your girl has some food in her system than none. When babies are sick it’s totally normal to give into whatever they want to keep them comfortable