Anyone CAN administer it, what the law in your area is I can not know. Here, an RN can do it, but it varies state to state. You want pharmaceutical grade vitamin C, intended for IV use. You can get it here: https://www.nutri.com/index.cfm/product/58/sodium-ascorbate-powder-2000-gr.cfm?gclid=EAIaIQobChMI9Ly4kO3K1wIVFcpkCh1jyAX4EAAYBCAAEgIQqPD_BwE
Good luck to you and her!