Oh my, I sigh as my proper Southern aunt would, I don't believe you were referring to little ole me because I clearly stated that I thought my daughter's "Eastern accent" was quaint and surely do hope no one took offense at that, but I just wanted to add that I never believed she "picked it up" as that would have been well nigh impossible seeing as we lived well south of the Mason Dixon line when she developed it, as did my adorable nieces at that age when they developed theirs. Nor do I think it is anything to worry my little head over because my nieces outgrew their "accents" with not the first visit to a speech therapist, neither a whoop dee do. But I sure do wish you could hear my accent as this goes through my head. It certainly entertains me and no offense meant, only great affection.
I certainly will be on the look out for a speech impediment, but as my child who now speaks with that "regional accent" began babbling and producing a range of vowel and consonant sounds at age 3/4 months and was "speaking" a tonal language as well as English at age 10/11 months, and as my nieces exhibited the same "accent" at the same age, I think I'm going to toss this up to a developmental stage and not panic yet. And that would be the advice I'd give IADad.
;-)