We have the commands as well, go potty is pee and go poopy is poop.
Brodie is funny; he goes 'potty' in one area of the yard which is where we always bring Kooper - it is our official dog area - unmarked - but both know to head there to do their business. But for poo, he can't seem to poo where he pees - he is very particular. He prefers to poo in our front yard or right behind the house. But the particular thing is, he only poos on the perimeter. We have low rock walls along my garden beds - he poos right along those beds. Even though he hasn't stuck to our official potty area, he's easy to pick up after.
With Brodie, we got pee daytime (piece of cake) and pee overnight (he only went out during the night like the first 2 nights when I woke him). Pee evening was a LONG time coming because evening is the witching hour when we become crazed, playful, psycho puppy for a few hours. He ended up wearing a wrap for that for some time; easy solution due to the male anatomy! Poo was easiest to judge because it coincided with food - what goes in must come out! But then just when we were patting ourselves on the backs for such a quick potty training with Brodie, he started pooping inside! Teenage angst, whatever, I think WE were trained but he hadn't gotten it yet.
He now, at 7 months on Saturday, can hold his bladder for ages, will try and tell us when he has to go which sometimes includes going to our powder room and barking if we don't get what he is saying immediately. Our first doxie was reliable unless it was cold or wet out, our current doxie was not reliable until 5 years of age. Brodie was a breeze even though I remember being so frustrated, and tired which doesn't help with frustration, for a few weeks that he wasn't getting it. Minnie will get it, just be prepared for a backslide which can happen later on - like she may suddenly get it with one and forget it with the other for a bit.
Our trainer says it takes 7 weeks for something to move from the short memory part of the brain to the long term memory part of the brain but there is a break in between the two when the memory seems totally lost. Not sure if it is scientific or not, but seemed to go along with our experience with Brodie.
...bad mommy I know but I wanted to crawl back in bed...had to take him outside lol.
A hand signal for pee would be interesting 
Now we can get her on a pooping schedule. She's also a snacker, 
for now anyways. That makes it a bit more difficult, but we'll get there. She's also starting to tell us when she needs to pee, she will start down the hall to the back door.