You may have 2 option:
1. If anyone of you is using a desktop, consider to deploy a private cloud. It costs $25/month/access
https://partners.myquickcloud.com/?pc=fiatlux
2. If you are using any supporting QB version (i.e 2017-2020) and both of you are using notebooks or mobile devices, you may put your own license and data files on an authorized QB hosting. The cost starts from $30/month
http://www.apps4rent.com/#a_aid=quickbooks