it strikes me that if she did have an allowance (you mention she has none to take away) she would have had money for the game without having to ask you. It is likely her friends were buying tickets then and she was embarrassed not to be able to join in. You seem really worried about teasing so i am thinking she has had issues fitting in in the past (perhaps?).
I also read your other thread about her not caring about school work. In both cases you talk about her having nothing to take away. Tis is a big red lag for me. Why does she have nothing she loves/care about to lose? No 12 year old should be living a life with nothing to look forward to or care about doing/owning. If she truly has no belonging or activities she cherishes (and she should have several) then you have much bigger issues on your hands than $5 spent pretty much any which way.
It seems to me, from this admittedly very limited picture from two threads) that there are a few things possibly going on here:
1. You are seriously overreacting to little things ($5 is not that big o a deal--she did not steal it, most parents would figure having not had lunch was punishment enough. I would probably not let her eat a snack and be hungry until dinner time an that would be the extent of it, oh and i would ask her why she didn't just ask for the money for the ticket: Was she afraid to? Did she forget? Is she worried about our financial situation? Etc.).
2. You may be overly controlling of her life. You have not provided an allowance or anything else she values enough that it would bother her to lose it. You have not provided her a fun activity to look forward to (which can often help motivate a student). You have not provided her with belongings she cares for. You have not fostered her getting out and socializing (so that being grounded, not allowed to sue the phone, etc would be something to take away). Essentially, you have somehow managed to not allow her to hae a life beyond what you are there for in the moment (she doesn't even ave $5 for a ticket to a school event without asking for it--which for some reason she can;t or won't do).
3. She is depressed--thus the apathy related to school and not caring about anything enough for its loss to matter.
4. She is overwhelmed with all of the responsibility of middle school and forgetting things and shutting down when it all gets to be too much. She may also be struggling academically and not just being lazy (things really pick up at this stage and sometimes really bright kids with learning disabilities can compensate right up until this point and then suddenly hit a wall--having compensated before no one knows there is an ld there and they feel "stupid" at that age so do not ask for help and parents just see laziness. This could be compound by her reluctance to bring things to your attention--even little things like needing money for a game ticket).
Honestly, in light of your other thread, i would respond to this with compassion and love and apologize for having ever given her the impression that she should have to choose between lunch or the game--set up an allowance asap and then watch to see where else the problem lies. Good luck.