Breeder rescue terrified of humans

Hello, I rescued a 5 year old mini schnauzer who was a breeder dog then dumped at a kill shelter. We’ve had her for two weeks and she is still TERRIFIED of me and my partner.

My concern is that we live in an apartment, so we haven’t been able to take her outside yet. She spends time on our balcony for fresh air, and she's pretty good about using the pee pads inside. But I feel guilty not giving her access to grass/other dogs, things that I think might help her gain confidence.

When we first got her she hid all day in an isolated corner, which she still does, but she’s started exploring the apartment, approaching us to sniff, and waiting near the kitchen for treats- so we've made some progress, but not in regards to her behavior towards us. Whenever I try to get close to her, she immediately runs away. I don’t want to rush her decompression period because she's clearly been through A LOT, but need to figure out how to get her to let us touch her so we can get her outside...

If anyone has advice please pass along, we need it!