Yep, you can transfer your data from your console to an SD card, then from the SD card to your daughter's console.
I'm not at home to do a step-by-step, but basically you get an SD card and put it in the slot on the front of the console. Then click on the options menu from your home page. You'll have two choices; pick the one regarding data management. Then go to the console data (not SD card yet). Cycle through all of your save files and when you find your Wii Fit file, click on it, choose 'copy', and copy it to the SD card.
When you get to your daughter's house, put the SD card in her machine, go back to the data management section, but this time go to the SD card instead of the console. Copy your Wii Fit file to the console, and you're set! When you leave, you'll want to copy her save file to your SD card then put it back on your console (so you have everything you did while at her house).
Only thing I'm not sure about is how your Mii comes into play. You might have to copy him/her as well, and I haven't done that so I'm not entirely certain how it works.
Sorry if these directions are awful; I haven't copied data in a while, and while I don't think I'm missing any steps, I'm not sure my descriptions are as useful as they would be if I was at home. Good luck though and I hope it helps!
Keri ~ Illinois
"The difference between try and triumph is a little umph." - Marvin Phillips
"Never give up on a dream just because of the time it will take to accomplish it. The time will pass anyway." - Earl Nightingale
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