I wouldn't push your mum to eat or take medication if you think it will make her very aggressive. However, if you think it is worth a go, will she eat if you eat with her? What is her favourite thing to eat? Often sweet stuff if more appealing or something she can just pick up like cubes of cheese, sausage rolls, cream cheese on small pieces of bread etc, "finger food" that's easy to pop in. GP may be able to advise if med's can be in an easier form to take.
I'm sure the tea is helping! At least she won't be dehydrated.