I use picassa as well....I right click( all pics) the folder of the pics Im gonna resize...then hit the "export" folder ...in there you can resize them to what ya want...Hope this Helps That Girl...and sorry to hear of the Girls sex change...
right click picture
select open with
in paint on the toolbar it says crop, resize, rotate
click on resize
I change it over to pixels and change the larger number to 1200 the other automatically changes.
I use a program called photoresize. Here is the link. Just replace xx with tt. Dload it to your desktop. Drag and drop the photo to the icon. Hit run. A box will pop up then hit enter. The resized pic will be put in the original photos folder. Simple as that. Good luck!