Seamless Person Swap in Selfie

I need a clean, high-resolution edit where the person standing next to me in a selfie is replaced with how she looks at a separate photo. I want to keep the original post (with the beanie) but use the brunette person from the other selfie and to be added to that original photo. The finished image will be shared on my social media, so the swap must look completely natural—skin tones, lighting, perspective and shadows should all match the original capture.

Please work at full resolution (no down-sampling) and deliver the final file in both JPG and PNG as soon as possible once the blend is perfect. If you need the raws or reference shots, let me know right away so we can keep the turnaround fast.