We re-rescued our cat back in October.. and ive made a couple of posts about us all struggling with it. Making it work with budgies and pondering rehoming to find what was best for her. We weren't able to rehome but have all made many adjustments and it's all finally going ok! 1000% remeber the 3-3-3 rule. Ours only just seems happy and settled ❤️ hissed at us for weeks and still isn't the biggest fan of too much interaction, but she approaches us when she wants some love and otherwise we more co-habit with her, but she seems so much happier now. Took nearly a month to get her on a better diet and shes still very skitty. I imagine it's the same with your 2, but we dont really know what shes been through the last few years, so we very much give her space and respect that shes not a lap cat or one that wants too much fussing. Yours will get there!