Hello! That's really quite sweet of Isabella, but I can see how this would be problematic to your cats. Frankly, there is no simple way to change her behavior other than intervening and telling her "no" when you see it. Issues like this usually require management by providing the cats with ways to escape, rather than expecting the dog to change. Depending on how agile your cats are, it may be beneficial to put up baby gates to keep Isabella out of a room where the cats can choose to escape, or provide more elevated and protected areas such as a cat climbing tree like this one:
https://www.chewy.com/frisco-52-inch-cat-tree-cream/dp/119898?utm_source=google-product&utm_medium=cpc&utm_campaign=hg&utm_content=Frisco&utm_term=&gclid=EAIaIQobChMIn-uNiJml1QIVU5R-Ch2P2gFNEAQYAiABEgKxMfD_BwE&gclsrc=aw.dsI know this isn't a perfect solution, but it's natural for many dogs to want to be a bit more interested in cats than the cats would like them to be. Usually we can't change that, so we have to give the cats ways to escape so they can be comfortable. However, if you do want to work with your dog at correcting the behavior, it would be worth connecting with a good trainer who can come to your house and watch Isabella in person - your vet should be able to offer recommendations.
Hope this helps!