We had this for New Years! My husband had family over and one of them started coughing whilst holding one of my babies (they were 9 weeks old). The next day, we got a message saying he's got a cough and they were just letting us know so we could avoid seeing them if we wanted. Anyway, we sprayed down their hands with Vital Baby cleansing water (and face once one of them kissed a baby on the cheek

which I'm still not over almost 2 months later). Unfortunately a few days later my 4 year old started showing signs of illness and then a few days after that our babies did so I don't even think the babies picked it up from there but our son must have and then passed it to us. My 4 year old was born 41+2 and caught RSV at 4 weeks old and bronchiolitis at 10 weeks ish and that was with us being VERY careful because of COVID and our family all had to wear masks and we didn't see them very often. It was a very scary time in and out of hospital so with twin babies born prematurely I was dreading them going through the same, especially when they did get ill (thankfully a bit older than my first). Thankfully it didn't last very long, it started with a cough and then their noses would get blocked so we just used a saline spray and that would help them feed and breathe etc. They just rode it out with no hospital.
Hopefully your little one will be okay and this was a long message with a whole lot of nothing really but just to reassure you that even with being coughed on mine were okay (was just their big brother I think haha) so I hope that the RSV jab I had whilst pregnant did the job (it wasn't a thing for my first) and even if they do get ill it doesn't always mean hospital! Just keep an eye out and if they start a cough just prepare yourself and be even more vigilant x