To me, this is a complete illustration of why sending 6 years old into formal learning, as if they are 10, or 15 is wrong. Doing nightly homework is ridiculous aged 6, they have 7 hours a day in a very cooped up environment, doing far too much sitting on the carpet and far too little art/music/humanities/creative play. Then they get home, and instead of relaxing aged 6 with their family, building bonds, having cuddles, playing with siblings and learning different life skills, they have to sit and do homework. Furthermore, parents and children who are working, busy, have other activities on (ballet, music, Brownies) can't do the homework, let alone parents who just don't give a shit, or who can't help (my dd aged 6 gets homework which she can't read herself, so an adult has to read it aloud to her, so she is not able to self-complete).
Mine do 20 min to an hour A WEEK. We read and practice spelling daily for 20 min If it goes over that, I write a note explaning we did not have time to do more than this.
Prioritising silly homework aged 6 over family life is ludicrous, and if you only get one night to do it, I would mention this to the class teacher and then the head.
All of this depends on parents being able and willing to supervise homework, children cannot control this aged six and so I think your daughter was rightly upset about something that was not really in her control.
The crying after being told off is no big deal, except again, what type of learning environment is this? Mine don't cry when mildly disciplined by the teacher and I wouldn't expect more than a small reprimand or a 'come and sit over here, you need to do as I say'. Everything else is heavy handed, and more likely based on the teacher worrying about SATS results at the end of that year than the children loving learning.
I just don't get it, there's no need for it, other countries don't do it, and children in the UK are not better educated or more literate aged 16 for all this homework.