Does what the groom's grandmother did—giving her breast to her cousin's daughter, and the girl latching onto the breast—count as prohibitive suckling (radāʿ muḥarram)?

For fosterage to be prohibited (making marriage unlawful), it is stipulated that there must be five full sucklings where the milk reaches the child's stomach. If no milk is emitted from the breast, it is not considered a prohibiting suckling. Furthermore, prohibition is not established when there is doubt about milk being emitted.