Parents' evening woes

What a long time it's been again! I'm taking that as a good sign, that I didn't feel the need to let any traumas out here, rather than a bad sign that life is still so manically busy I don't get time to update.
And there is plenty to update, believe me, but that's for another post...
In the meantime, it's time for another bout of free therapy - just till my next paid-for session, of course...
So this afternoon was parents' 'evening' at Miss T's pre-school. It was our third, or fourth, and all the others have been absolutely fine - she's quiet, she's settled, she's confident. There was no reason to suspect anything different this time.
Even when I was left waiting a long time to speak to her "key worker" I wasn't concerned as that has happened before.
But after about half an hour the pre-school manager, no less, came and sat down and said as her key worker was still busy she would start things off with a "word about her behaviour".
I think those are words every parent dreads. I've never been pulled in for a "word" in the 10 months Miss T's been at school - apart from once when another child used her as a cushion. She doesn't exactly have a host of behavioural issues, apart from usual three-year-old stubbornness.
Until now. Apparently Miss T has been spotted doing "sneaky pushing". Not just pushing in a row over who gets what toy, but pushing AFTER an incident like that. The example the manager gave started as a tug of war over a hat. When she intervened and reminded Miss T the hat belonged to the other child she let it go, but was spotted a few minutes later going up behind the other child and shoving her. Not hard, admittedly, but still a shove.
And according to the staff, this happened three days in a row, on top of about three weeks of other, similar incidents.
Of course, they tried to reassure me - especially after I ended up sobbing into a tissue! - and said she was nowhere near the worst they'd seen, and most children go through similar phases, and there had been no incidents during the two weeks since half term, but all I heard was 'My daughter's a bully'.
It wasn't the pushing so much that bothered me as the spitefulness of shoving after the initial incident. The word they used was sneaky, and I wasn't even reassured when they said how surprised they were to see her behaving that way.
Their advice is to leave it for now, praise her for good sharing and playing nicely and "kind hands" but I'm finding that rather hard.
Of course she's not perfect and there have been pushing incidents before, but I've always dealt with them on the spot and they have been more 'understandable' eg during a row over a toy etc.
But I never expected to hear she seemed to have this rage inside her or a desire to hurt.
And of course I can't help wondering if there's a link to everything else, ie me and my madness.
Rationally, I'm sure there's not, this is just a phase - and one that by the preschool's own admission seems to have stopped - and not a red flag for future mental health issues. But that doesn't stop the guilt.
Maybe she picked up on some of my rage from when she was younger. If you don't remember - and I wish I didn't - try this for an example: http://ihadpnd.blogspot.com/2009/04/spoke-too-soon.html
Maybe it was because we didn't bond for months and months and there were times when I ignored her crying.
Maybe it's because I work too much.
Maybe she's picked up on other changes at home and they are making her unhappy.
I don't know. I don't know if I will ever know. And that's very hard.
It's also hard to know my beautiful little girl, who can be so gentle and so loving, also has this nasty side that's very hard to like. Of course she will struggle with her emotions in life and won't always be perfect, but I wanted to hang on to my sweet little girl for just a little bit longer.