Risks of unwittingly spreading Covid

[Squittly]

Jane and Sarah share a house but have bedrooms on different floors and do not share a bathroom. Jane has had one dose of vaccine, Sarah has had both.

On Saturday evening Jane meets up with friends. Sunday-Tuesday Jane and Sarah barely see each other, just in passing as both are WFH.. On Tuesday evening Sarah meets up with friends.

On Wednesday Jane’s friends report to her that they have had positive LFTs. Jane has had negative LFTs since Saturday (she takes them most days) but Wednesday’s is positive.

Sarah’ takes an LFT and it is negative.

All parties will get PCRs ASAP.

Is there likely to be much of a risk to Sarah’s friends? Could Jane have caught and already passed on Covid between Saturday and Tuesday?

Obviously if Sarah tests positive she will inform her friends but in the meantime she is worried about the risk to her friends, all of whom are double vaccinated.

(I’m Jane in this scenario, Sarah is my sister)

If Sarah’s friends have not had contact with Jane, so don’t need to isolate, but Sarah does as she lives in same house, although on different floors. I think it’s wise all of you getting PCR tests done, you will know one way or another.

It depends if you infected your sister; if you were the original case then you might have infected your friends too. If not then you isolate from now but can't have passed on a virus that you didn't yet have.

Hmm. If you were just housemates then your odds of passing it on if you “barely see each other, just in passing” would probably be low. My suspicion would be that sisters would probably instinctively get closer on those passing meetings but only you know. If Jane really did contract the virus from her friends at the meeting on Saturday it seems slightly unlikely that the timings would work for Sarah to have contracted it from Jane and it have developed enough for Sarah to pass it on to Sarah’s friends on Tuesday, but unless Jane has been otherwise housebound it’s possible that she actually caught it a bit earlier and the meet up was a coincidence.

I don't think anyone can say realy, seven days after my son tested positive both myself and dh are still testing negative on LFT, s we are both fully vaccinated, but we live in a small two bedroom house with only one bathroom, and hes my son so when he wasent well for a couple of days last week i hugged him etc

Thanks everyone, I feel a bit better that it’s not terribly likely to have spread further, I would have felt awful.
We’ve had PCRs and are awaiting results.