You can see in this photo what a big difference there is in length around the hem. The longest point is on the true bias.
I had no helpers when it came time to mark the hem, so took a deep breath and did it solo. I put the dress on and marked where I wanted it to hit. It was quite a challenge to hold it steady against my thigh while I marked a point just below my knee! From there it was a simple matter of putting it on my dummy and marking it by measuring up from the floor with a long ruler. My fear doing it solo is that while my dummy is very similarly proportioned to me it isn't as accurate as getting a helper to mark it on me. I figured it wasn't going to be significantly out even if it was a tad. (I've done this before with success, but not for a while). I have one of those chalk puffer thingies for marking your own hems, but I'm, um, not sure which box in the roof it's in.
Anyway, after doing my baby hem on the dress and pressing it and putting on a decent bra (which makes a huge difference!), it looks like this:

And here's the one she took of me and David just before we left. That's Nicholas' head in the corner. Nothing happens in this house without his investigating! David's shirt is one of approximately 15+ I have made over the years for him or his twin brother. It's my absolute favourite, Burda 8471 I can churn one out in no time - the fit needed very little tweaking, so he doesn't need to be involved till I hand him a completed shirt. He likes this.