Birthday cat is now almost 6 weeks old. I have started to slowly introduce him to his big sister. I'm quite pleased that they are actually getting along very well. Birthday is weaning from the bottle and is eating Royal Canin babycat dry food, drinking water from a bowl, and using the litter box on his own. He will go to the vet for his vaccinations soon.
I limit their time together, but let him crawl around on the floor a while each day. He always makes his way over to where Sierra is. Looks like this might be a good match after all!