What do I do about this work collegue/friend?

SORRY but I need to get this off my chest to mutual people.

Okay here goes…
In the school I work in the children pay £1 snack money, this allows me to buy snack and extra resources the class may need. The other teacher I work with does the same. Sometimes we borrow packets of biscuits etc.. from each other. However my TA bought some special bits for the children (enough to last until the end of term) the other teacher spotted them and said “Oh you have bought snack” and started to help herself. I said, ” Oh don’t take any just yet, my TA bought them and she has bought special stuff for the kids, you’d better ask her tomorrow, I don’t want to be in her bad books” and the reply was “But we always borrow off each other.” I agreed and said, “I know but be it on your own head if you take something that she bought specially for them” following this conversation she started talking to me in 1 syllable answers and then instead of walking out of the door together as normal she went on her own. She didn’t repond to phone call or text on way home – something we always do at the end of the day so the journey passes quicker.
So what do I do?
We usually get on really well, so much so we are going out on Saturday.
I know this sounds silly but I feel like I have really upset her and I don’t want to. I don’t want it to become a big issue.
I spoke to my TA about it and she said it’s fine she can have some (which I knew she would but didn’t want anything taking just in case something was particularly for our kids)
I know I should just go in tommorow and act normally as I don’t have any issues. But I don’t want things to be left. I have a feeling she will go out and buy stuff tonight so even if I offer it tomorrow it will feel like it is an empty gesture.
Silly and petty I know but things like this really worry me, I don’t like upsetting people.

Do I confront the issue tomorrow or do I carry on as if nothing has happened?