Supposedly Sarah's birth year is 1945 (according to a Twin Peak wiki, maybe there's other sources for this?) which would make her 11 in 1956. The Log Lady would have been 16 in 1956. Which for me fits the age of the girl. Plus, The Log Lady would already be known to them and them to her, potentially.

The girl called by Margaret, the log lady, her birth year is given as 1940 and she'd be 16 in 1956. Potentially the boy could be Carl, the Harry Dean Stanton character.

Does nobody recall Cole in the diner kissing Shelly in the original series, and making a point of kissing Shelly while Bobby looked on? Presumably that was 'sweet' rather than 'sour'?

The first LP was called 'Weird Sister' not 'Weird Sisters'