There’s definitely things you can be doing to improve the taste for your partner. Mostly it’s just being healthy, hydrated, active. Avoid smoking and unhealthy foods. I think zinc and iron are good too, there’s plenty sources online worth looking at. Other foods like pineapple seem to help too. Lovehoney also sell an amazing ptoduct called Yummy Cum which is well worth trying! A combination of those works for us, see what works for you.
Could also be it’s not really for her though, its not for everyone. There’s other fun to be had than swallowing. As I mentioned I sometimes just let it drool out my mouth which can be really sexy too!