as a person who's been experimenting on.... coughs.... over 30 saves since august last year, it's easy (atleast for me ;u;)! when you got lala, make sure you haven't leveled up any cats from the house level! not even bred (who you should have to get the chances of getting lala higher!!)
level up lala with them! they should atleast get to level 8-10. then go to the computer, and then house, and back and forth. then level up lala with your fishbones! you should be able to get through computer levels 1 and 2 smoothly.
then, level up lala with the fishbones! you may have gotten strawberry from the level 2, but don't use strawberry! they miss frequently, which gives them a disadvantage with angel neko. for example, if they miss with angel neko, they get an effect. while under the love effect, plush hits. there's a chance they'll get a distracted effect.
use lala (who would be at levels 13-15!) to defeat! target angel neko first. when it comes back to angel neko after plush, pixel cat and strawberry had their turns, use joke! angel neko is under the music effect. not many people know this, but when using an act, the cat never gets out of the effect, so you may continue attacking angel neko while the other three have turns again!
there's a chance of getting angel neko when you decline pixel cat! it didn't work for this time, but the shop is still open for random draws and buying. angel neko is... expensive, 20 coins ;u; so it's your best shot random drawing. you might get plush, which is better!
if you got no luck on that, use lala to defeat woods level 1. the fields are still locked when defeating the computer. you have a big chance of getting wood! wood has a max of 75 damage, the second highest (highest is 85!)
for the last battle ~
don't hesitate leveling them up to 99! caticorn and angel neko are the best cats to defeat the royal family with! there are also prince star and rainbow with the same stats, but their attacks have no effect (nothing like scared, love, etc!) while caticorn and angel neko have love!
for the battle, defeat cats in this order: night queen > cloud king > prince star > princess leaf! princess leaf should be left as she misses often, with a max damage of 58. it may be hard to get through prince star, but luckily he's the only real threat with magic and 53 (56 once completed and replay) damage. night queen and cloud king miss often with powerful cats, ESPECIALLY cloud king.
hope you have fun!! if you need further help lmk!!