I'm so sorry to hear your baby passed
I have 3 females and I got them seperately. Lola was 10 months when I bought home 15 week old Lea. the first day was very hard but within a week things were good. Lola is know 3 and Lea 2 and I just added Gracie at 6 months. I anticipated resistance from the other girls when I brought Gracie home and it went smooth as silk. Lola being the first born-diva surprised me. For me I think potty training them together would be easier in my opinion. As for living with the 3 girls they get along great without the female "sassieness".