What to say to family who disagree
You will not win this with evidence, and you should not try to, because the argument is not really about evidence.
The sentence that works is the one that takes nothing away. We are not stopping anything. We are adding one appointment.
If you need a second, use the one from lesson four. The bedouins asked the Prophet, peace be upon him, whether they should treat their sick, and he told them to use remedies. That is Tirmidhi 2038 and it is graded sound, and you can hand somebody the number.
And if you get nowhere, you do not need the whole family to agree. You need one adult and one appointment.