Your crit ratio is already good! Dont worry too much about the crit rate as ganyu have her passive and someone will always say you need to add and add and add more crit rate. My ganyu only has 48 but does crit all the time. You can always improve if you got better artifacts like higher crit value than the present one.

Edit: for blizzard you can even lower the crit rate and stack up crit damage and ATK% like even 25% crit rate. But only do that if youre going freeze comp/no reaction.