And since the addition of Catio, they'll have lesser burden in magic research hence more time to practice other magics
Was she ever against learning other types of magic?
No but she's old enough to want to find ways to pursue different magics without the need for approval from adults
the setting they're in quite literally prevents that though and she was pretty much encouraged to continue learning fire magic for the floors
That is true but it's also part of the reason han sent her to potion making, which is something she's never done before. And remember this is the reason we have at least 3 parties so parties can rest and retrain and they weren't always pushing floors either, there were substantial gaps of time where they were just back home. And just because you are encouraged to do something doesn't mean it's the only thing you have to focus on, fire girl just wasn't used to having to do things physically intensive or researching other things(kinda paraphrasing reading weekly kinda makes me lose the plot) so she was more tired than she'd like to be. Part of the reason han was trying to raise her stamina was so she 1. Could survive in hard conditions 2. It would build her body to help with magic. If she really wanted to she could have started learning associative magic and han would have been fine with that, although he's a crazy boss he'll help out his teammates if they want to do anything for improvement
Girlie has been too stubborn with learning one type of magic, even assistance magic like wind could help her fire magic, everyone has to adapt to her because her fire is reckless but she hasn't tried to refine it more. I understand she's been working on other stuff but you know how they say like if you doodle in your book everyday you can get better at drawing. If she fiddled with different magic everyday maybe she would understand a small amount of it and then figure out ways to use it efficiently