Hi!
I would encourage you to begin tethering / tie outs with your chi.
This would mean, when not in her pen, she would either be tethered to you (on a 1.5m leash) or tethered within sight of you and close by.
Establishing a routine which fits your current situation will also be important.
To establish a bit more clarity, you could also begin teaching your pup to use a "bell" to signal to you when she needs to relieve herself.
There are a lot of videos on Youtube on how to do this.
Let me know if you'd like more information!
www.topdogpawformance.com