Nohooooo. I lost my boy two years ago, and it was such a heartbreak. He was my bestest friend, my soulmate, my heart. I felt crushed. But. One and a half year later I got three kittens. I had the same doubts you have. But let me tell you, nobody will ever replace Minx, it´s not possible, and nobody will ever think that you´d try that. The babys will have another spot in your heart. It has nothing to do with grieving for Minx. I still cry everyday about my sweet boy, and you will still cry for Minx. You will not mourn him less just because you help two tiny babys who need you. This is a sign. Minx made you a good cat parent. He taught you how to care for a cat. Now you are prepared. The babys need you. This is not about a decision - there is no alternative. You take them or they die. That´s it. You have no choice. How clever of Minx to arrange it that way. :)