Emili

Pretty darned good for a first roll!
Pretty darned good,period.

Nice work Rich, hope you've developed hundreds of rolls since and will post more great pictures.

She looks to be in the myst of melancholy

Nice Photograph.

What's the effect that seems to emerge from the grass on her left, go the crook of her knee and almost disappear then re-appear on the grass in front of her and carry on to the bottom middle of the picture?

It looks to be grass to me.

From what I can tell, it does have an effect on the shades of grass behind it, but I think it is from the movement of a long grass, slightly wavering, in front of the lens.

Also, if you look at the top starting point of the visual, the light line seems to blend in the other grass, before it reaches the side of the negative, and the arch of the light fits what I'd expect to see in a long bladed piece of grass rising up from the lower middle of the frame.

Did you see the same effect in other frames, from this camera?

Correct, it's just a blade of grass that happened to be in the frame in the foreground.