When we got Sam she was 10 months old and Loki was and still is afraid of other dogs. They avoided each other for about a week and Loki wasn't sure if he liked her. Once he figured out she wasn't leaving he started to like her. Now they wrestle and play all day long. She kinda beats the snot out of him because he's a easy target, but we don't have any fights or aggression issues. They bark at each other over who's stick it is, but they know if they get into it I'll just take it away so they get along. They are good for each other
Look one day about a month after we got her we found them on the couch like this. They have been friends every since.
ETA: I was worried about some jealousy issues because Loki usually freaks when I pet other dogs, but I'd worked with him a ton and for whatever reason, he's not jealous of her at all. He lets her drink water first and he's a pushover with his toys and treats and things. He doesn't care if she's on my lap. I think they know they are stuck with each other and they totally act like brother and sister. One minute they are playing the next minute it's "Mom he's touching me!" Like I said they are good together.