@Ckone2541
You can each have separate membership and apply for the overlapping sit with the other account .
There is a test being done for Co- sitters which is trialing permitting couples (where each member has had their ID verified ) to apply for sits that overlap by up to 48 hours .
It’s in the testing phase only and only a few couples were selected to take part in the test . So maybe in the future it will be possible to have a joint membership that allows you to overlap sit.
Here is a link to information about the Co-sitter Beta test .
https://forum.trustedhousesitters.com/t/join-our-co-sitter-beta-group
For now overlapping sits are not permitted so the only work around is for you to join separately ( two memberships ) and each create a sitters profile .