ok i'm thinking of getting another dog in may

so these are my top picks
1.yorkie
2.another maltese I already have one
3.morkie(maltese and yorkie mix)
but i can't decide help me and my mom are debating about it
my last question is don't you think it's a better idea to get a puppy or a adult

it doesn't matter to me but it does matter cause of my maltese shes 11months know almost a year

but i don't want her to be bullied by a older dog

but i know she wouldn't bully a younger dog cause shes so sweet,loving and a lil shy

so I know that won't happen but what if it does?