Syrum

Star paying attention to her. Notice what she likes, what she doesn't, buy things she likes to eat, and other small things you have noticed her talking about. Like a movie she wants to see or her favourite movie of all time and watch it with her.(My fiance does this and it makes me feel very loved by him.) Do this before the anniversary and continue to do it. Notice when she puts an effort in to look nice and admire her.

For the anniversary, I agree about taking her away somewhere.
Book somewhere she would like to go, do not consult her, do not tell her about it. Organize with her work for her to have the time off (if she works), you call them tell them you are organizing a surprise, they will be so happy and thinks it's so sweet, her work won't mind.

You call and organize people to look after the children, again they will find it so sweet that you are doing this , they won't say no.

Then the night before tell her to pack for that you are going away in the morning and not to ask questions. Let her know that you have it all worked out.

She will be thrilled that you organized it all on your own and took care of everything. While you are away focus on spending the time doing lots of lovely things together.