Babys cough keeps waking her up

My baby was sick during Christmas 😔 now she only has a cough left but it’s totally disrupting her sleep. She rarely coughs during the day but when I lay her down to nap she can’t stop coughing she can only sleep like 5 minutes at a time without waking up and crying 😭

I’ve already given her a warm bath before bed, hung a wet towel by her crib, put a bag of onions by her feet, given her some homeopathic medicine for babies and rubbed baby Vick’s on her chest but so far she’s still coughing 😞 oh and I elevated her mattress so that she’s not laying completely flat

Does anyone have some more tips please?!