Put a note through her door with the following on it ... "Just want to say thanks for the presents ... Curiosity (and impatience) got the better of me, and I decided to open them. So you can imagine my astonishment at finding a winning lottery ticket - not quite a bumper jackpot, but ?0.8million is close enough for me

if you want the rest of the pressies, then you can collect them in a month when I get back from The Bahamas. Yours very gratefully, Claire xx"
I think she might be over sharpish then