In this episode, Alison is pregnant and seemingly dreaming of the child she's carrying. In Sweet Child O' Mine (S2, Ep 15), she references losing a child (boy) that would have been the eldest child, a number of years before the wedding. In this episode, she had not yet met Joe's parents, leading one to believe they had not been together all that long.
In season 5, episode 10, Joseph asks how Alison knew details of a murder (from her dream). Even putting that time line at Marie's pending entrance into the world, the discussion in this episode of her knowing of his cousin's involvement in a murder means he would have known about her gift in the season 5 episode.
The town of San Luis Obispo is mispronounced by the characters. They pronounce Luis as "loo-wee" but the correct pronunciation is "loo-wiss." Also the town is not on the beach. It is actually approximately 11 miles from the coastal cities adjacent to it.