Whilst weighing in at fat club this morning 
Was the second in queue so pacing about giving first in line some space, then a very friendly woman came up to me, all smiling and big hellos.
I thought she was just being very friendly, and didn't recognise her, so I just said hi, and carried on pacing about. Probably coming off as a bit stand-off-ish.
Got the weigh in over with and sat down and overheard that friendly lady had missed her regular (last night's) session elsewhere, so dropped in for weigh in only then was off, not staying for this week's pep talk etc. Also overheard her sounding off about this week's start of term and realised she was talking about my youngest's school, due to the specifics she was complaining about. (100% certain no other school could have had the same start of term complaints).
She swiftly left, then it dawned on me that perhaps she had actually recognised me in the queue, and now knows that I either didn't have a clue who she was, or I did and chose to ignore her!
I am now mortified at both.
Described her to my son when I got home, and he said she sounds like HoSF. Checked school website, and there she is. Definitely her.
Son will be seeing her regularly for the rest of the year, as he has a particular role in the school which means they have a full year of direct contact.
Every time she sees him she is going to think that I am a bit of a tw*t isn't she?
What CAN I do?