Yes, multiple practitioners can create "profiles" for the same client in Practice Better. Although we require a unique email address for each client in your account, there is no restriction preventing other practitioners from adding and inviting a client with the same email address that existing in your records.
If your client already has access to the Client Portal and is invited by another practitioner (Practitioner B), your client will be prompted to sign in to link her existing login credentials to the profile created by Practitioner B.
Your client will then have access to both Practitioner B's resources and your resources when she signs in. She will see a profile picker asking her to select between you and Practitioner B:
We will be providing true team support in an upcoming update which will allow you to share resources for an existing client with other practitioners.