I got the go ahead for spaghetti straps for the princess dress. Here's a sketch of the re-designed bodice. I'm not sure what fabric I'm going to use...something inexpensive as we are, after all, talking about a play dress. Another reason for an inexpensive fabric is that I think it's going to take yards and yards of it counting petticoats, etc.
But at the same time, I want it to look very princess like. I haven't been to the fabric store in ages - it's safer that way - but I think it's time for a trip.