Hiking and Lighting?

[abhishes]

I have stupid question. I hike with my GF and I absolutely love to take portraits of her. She loves to pose for me too.
We go on very long hikes and we don't have assistants. It's hard for me to carry lighting equipment on a hike because it's just too heavy. We also don't have power sources etc.

Given the above, we are only using iPhone 15 Max Pro and Post processing and while we have got some spectacular portraits ... harsh shadows on face continue to be our enemy.

Given that, can you recommend any equipment which I can use to negate the harmful effects of strong light? I can think of reflector ... but reflector can easily be blown away if there is wind.

So I guess the common sense answer is nothing... but I thought I'll check.

Stupid question... is there an external flash which can pair with iPhone? that way I can do strobes and iPhone?