My daughter urinated on my jacket with my iPhone 6+ in the pocket

Unless your daughter somehow had solid urine then this covers your case…

https://support.apple.com/en-us/HT204104

Liquid damage to iPhone or iPod isn‘t covered by warranty

Service for the liquid damage to an iPhone or iPod isn't covered by the Apple one-year limited warranty or an AppleCare Protection Plan (APP).

Search your copy of the Apple care terms & conditions for 'liquid' and you should see that clause. Apple don't list every possible liquid for obvious reasons - 'liquid' covers the most problematic ones.

You have to consider that all bodily fluids are potential carriers of infection or other hazards. Obviously I'm not saying that is the case with your daughter but you have to consider that even doctors an clinicians avoid direct contact with other peoples excretions where possible.

You can look for a third party repair company to see if they will handle a repair instead. Just be aware that third party repair companies may only want to get the device into a state where data can be recovered. Liquid - especially ones containing salts, ammonia & other corrosive materials will cause corrosive damage to occur over time to components. There is really no way to clean electronics & guarantee it will continue to work as normal. So your device may fail again in a few weeks or months. The best option is to buy a new device & restore a backup.

If you feel you have a case you should seek legal advice based on the questions you asked when taking out the plan. I suspect it seems like it would simply be your word against the store's especially as the terms of the warranty & Apple Care cover the liquid damage scenario. Even the water resistant Apple devices are not exempt from the liquid damage clause.

ADH coverage only applies to an operational or mechanical failure caused by an accident from handling that is the result of an unexpected and unintentional external event (e.g. drops and damage caused by liquid contact) that arises from your normal daily usage of the Covered Device as intended for such Covered Device.

I would expect some resistance when you try to persuade them that urinating on an iPhone is normal daily usage.

If you feel it is covered by the accidental damage and handling (ADH) clause you need to make that case to Apple. Visit the store again & ask for a replacement device under that program & offer to pay the $99 fee for a refurbished device. If you ask for a repair they will tell you it is a biohazard & refuse to do it.

Seal it in a ziplock bag & explain the situation again. If you are lucky a genius will make you a better offer, they have a certain amount of discretion to offer replacements. I doubt Apple will repair it so you should look elsewhere if that is your aim. If you have recent backup (iTunes or iCloud) you just need a new device.

Otherwise start a claim via the options listed on that page (via the web or via telephone). Apple may dispute the claim again but persistence can help.

Well, all that matters is what Apple think, so, good luck.