As I often tell my students, it's more important to have stretched legs and good placement, than to squish into fifth.
I absolutely agree with that! Not many people can get the toe to heel look, and I don't think it matters that much. From what you describe, it sounds like it is that bad (from where I'm standing, i.e., not being able to see you! :p )
Can you get both legs stretched (this is a better and more accurate term, I think, than straight)?
Dean, actually, on this occasion, I did mean 'straight'. I wanted to know whether it was a question of the shapes of the legs (which sometimes can prevent the "traditional" heel to toe look in 5th position). Sometimes, the legs are hypo or hyper-extended, and then, there must be some adjustments to be made in order to accommodate the shape of the legs (so that all fits together under the waist).
There is anyway (for everyone) a need to lengthen the spine in order to have 'room' for the legs to fit underneath. If you 'sit' in the position (i.e., let the weight of your upper body simply rest there on the hips), there will be less possible room for the legs to move and replace themselves in a tight 5th.