Toddler vomiting 3 times in 10 days - is she ill? Help!

[SylvanianFrenemies]

10 days ago DD2, who is 2, vomited just after her bedtime breastfeed. She seemed fine.

3 days later Dd1 (7yo) came down with winter vomiting - vomiting every 2 hours for a day, ill, lethargic.

2 days after that DD2 vomited again once during the night, again just after breastfeeding. She didn't seem ill, but I assumed it was the same bug as DD1.

I got the vomiting bug (vomited several times, felt awful).

DD2 has just vomited again. She seems fine. But could she be ill? To summarise, she has vomited on days 1, 5 and 10 but fine between. If she is not ill, why is she being sick? If she is ill, why does she seem OK and isn't vomiting lots?! Need to work out if we need to quarantine her from family on Christmas Day.
Help!

Day 10 vomiting (tonight) was immediately after breastfeeding while lying down.

Hmm...possible food intolerance? Over excitement mixed with diet?

Rotavirus if having runny bum too? (The vomiting can be spread out with this particular vomiting bug whereas normally its vomiting followed by days of loose bowels)

Thanks.

She's been vaccinated against rotavirus - would that rule it out? She had one nappy which was maybe a bit soft, but I cant say she's had diarrhoea. Do you/anyone know if we'd expect her to seem unwell with rotavirus?

She has maybe been eating more crap, so it could be that? I don't know that she is more excited than usual, she doesn't really get Christmas yet.

What's the vomit been like? Typical food vomit or different? At her age if she's having only vomit and no proper diarrhoea then I'm not medic but I'd be inclined to suggest it's more food related and a reaction to that? Could be worth trying to get a doc appoint today, whether through your surgery or OOH.