I am assuming that she is fighting you brushing her teeth? Kids do not have the dexterity at two to brush their own teeth. Most kids don't have the skills to do it on their own until about 8. So hopefully, you are the one doing the brushing for both kiddos. A minimum of two minutes for each kid.
This falls under the category of it not being up to the two year old. This is a non negotiable, because it puts her health at risk.
Both of my kids went through periods of fighting tooth brushing. Like you, we tried lots of pastes and brushes. Nothing really worked. Finally I bought a light up tooth brush. If we let my son hold it while it was lit, he would let us brush his teeth without fighting. If he began to wiggle, turn away or avoid the process, he lost the light up brush to hold. For him, that worked like a charm.
Unfortunately for our daughter, we really couldn't find anything that worked. We finally had to resort to holding her down to get it done. NOT fun, but I think we tried EVERYTHING else. Fortunately, we only had to do it a few times before she learned this was a non negotiable thing. She started "agreeing" to teeth brushing a little more. In the beginning she just chewed on the brush and we didn't push it. It was success for her. Then we started to brush more and more. She's 4 now. She still hate "spicy toothpaste" (i.e. anything mint), but fortunately there are many options out there and we no longer have a fight on our hands.