When you say “share the same account”, do you mean share the same user profile? If so, then that would not be possible as Glide will create a new user profile row for each user that signs in. You could add a 2nd email column to the user profile sheet and insert the spouse’s email in that column, but you’d have to do this for each spouse so they can access each other’s profiles (they would still each have their own profile).
What you can do though is have multiple email columns in a sheet/table so that you can have multiple users being granted access to the data in that row (you can use multiple row owner columns for this, or basic visibility conditions if you don’t need your data fully secured). If your data is in a “house” sheet for example, each spouse could be in their own email column and you can control access/visibility by using those columns.