Yes... you need to be careful during the replication process. The data will be overwritten. Recommendation is to not do any changes to the PROD while DR is being built otherwise these will get overwritten when you replicate the data back to PROD.
The way this will work is
Site1 has info.
Create Site 2. Import the data from site1. Create any additional data.
Import back to site 1. Site 1 now has data from both site1 and site2.
Regards
Girish