Can the deceased see us and recognise you when we make dua for them?
I haven’t come across such a hadith, but there are ahadith which mention the deceased recognising the person who visits their grave.
The Prophet Muhammad (صلى الله عليه وآله وصحبه وسلم) said, “If a man visits a grave, of whom he knows and says salam, the deceased recognizes him and answers his salam, and when he visits a grave of whom he doesn’t know and says salam, the deceased reply to the salam.”
[Sharh ul-Sudur page 202]
The Prophet Muhammad (صلى الله عليه وآله وصحبه وسلم) said, “If someone walks to a grave of someone he knew in the world and says salam, the deceased recognize him and reply to his salam.”
[Sharh ul-Sudur Page 202]
The narration below informs us that the deceased are also made aware when someone performs sadaqah on their behalf.
Hazrat Anas (رضي الله عنه) narrates that he heard the Prophet Muhammad (صلى الله عليه وآله وصحبه وسلم) saying, “If someone gives sadaqah on behalf of the deceased, Hazrat Jibra’eel present the reward in a plate of light, he stands at the side of his grave and says “O! The person of this grave, this is the reward gifted to you by your family” So he accepts it and it enters the grave. The deceased becomes happy and delighted and his neighbours become sad as they didn’t receive any gift.”
[Sharh ul-Sudur page 308 of Imam As-Suyuti]
Allah knows best.