Looks good to me.
Behira started on small rats about that weight as well (about 5 months ago). She's now over 750G (estimate - 710G a month ago but hasn't had a good poop since to get a good weight despite eating two rats over that span).
She has a similar build and acts and looks healthy. When she stretches straight out, she can look kinda thin, but she isn't. She's just getting long and hasn't filled out completely yet!
Everyone on here says she looks great (and the Boa peeps here have taught me much of what I know).
Keep us posted, but looks good!