I think your relationship with your employer has started to break down with the result that you are both becoming less flexible with each other rather than more flexible. You need to decide if you want to stay in this job or find another one.
If you do want to stay in this job, then work out your leave entitlement for the year and plan out when you would like to take it. Then sit down with your employer - either of them - and take them through roughly when you'd like the holiday, and say that you know they'll need time to think about it and discuss it with each other.
So for example between Christmas and New Year is a reasonable request, and is quite far out. It may not be possible if their work is particularly busy then, but asking now means they have time to look at other ways of enabling you to have that time off. If not, at least you know now.
Likewise, if you want a week over the summer at all, you need to have that conversation now. If they have a summer holiday planned, then it would be sensible for you to have the same weeks off, and making that suggestion will help build bridges.
It's unlikely that they will want you to have any other time off over the summer, so bear that in mind and think about going away in June or September instead when the children are in school.
When discussing leave, you could also indicate that you assume the time taken off for bereavement was part of your annual leave (assuming they paid you as normal for it?). If you do this, then I think they will relax a bit more, and will see that you are trying to be flexible and helpful to them.
Even a month's notice for a week's holiday is short - so as others have said, try give much more notice if you can. If you do, and then want holiday for say a day at 2 weeks' notice, they will probably be much more willing to try and accommodate it.