Want to allow other person in group access edit and review submission to my forms

How do I allow another person in my department to have access to my forms so we can work together on forms? and have it set up so that we both receive submission notices and can review and edit the same form?

The forms can be shared, but this can be done from the main account only. Here is a link to the guide: 

How to Share Forms with a Sub-Account User

Regarding email notifications, please take a look at the next guide:

Send Notifications to Multiple Recipients

If you need any further assistance, please let us know.