Short answer. No, it does not break the privilege. Rule 130 extends the physician-psychotherapist privilege to persons, including members of the patient's family, who participated in the diagnosis or treatment under the direction of the physician or psychotherapist — so a relative present to help with treatment stays covered, not an outsider who defeats confidentiality.
What the law says
This privilege also applies to persons, including members of the patient's family, who have participated in the diagnosis or treatment of the patient under the direction of the physician or psychotherapist.
Rule 130, Section 24 — Disqualification by reason of privileged communication[s]. Read the full provision →
What the law says
A physician, psychotherapist or person reasonably believed by the patient to be authorized to practice medicine or psychotherapy cannot in a civil case, without the consent of the patient be examined as to any confidential communication made for the purpose of diagnosis or treatment
Rule 130, Section 24 — Disqualification by reason of privileged communication[s]. Read the full provision →
The core physician-psychotherapist privilege
Rule 130, Section 24(c) protects what you tell a psychotherapist for diagnosis or treatment: a physician, psychotherapist or person reasonably believed by the patient to be authorized to practice medicine or psychotherapy cannot in a civil case, without the consent of the patient be examined as to any confidential communication made for the purpose of diagnosis or treatment of your physical, mental, or emotional condition, including alcohol or drug addiction. Without your consent, the psychotherapist cannot be made to testify about what was said in session.
Family present for your treatment stays inside the privilege
The rule anticipates exactly your situation and extends the same protection to them: this privilege also applies to persons, including members of the patient's family, who have participated in the diagnosis or treatment of the patient under the direction of the physician or psychotherapist. A relative who sat in because the psychotherapist directed or allowed it, to assist with your diagnosis or treatment, is treated as part of the confidential circle, not as an outsider whose presence waives the privilege.
What counts as a psychotherapist here
The rule defines the term narrowly: (a) a person licensed to practice medicine engaged in the diagnosis or treatment of a mental or emotional condition, or (b) a person licensed as a psychologist by the government while similarly engaged. Whether the privilege applies at all depends first on your provider fitting one of those two descriptions, and second on the family member's participation being connected to the diagnosis or treatment itself, under the provider's direction, rather than being unrelated to it.
This rule speaks to civil cases
Notice that the text frames the privilege as applying when a physician or psychotherapist would be examined in a civil case. Whether and how far the same protection reaches other kinds of proceedings is a separate question from what this provision states outright, so it is worth keeping in mind what kind of case your communications might come up in.