Yes. On your 3DS, go to the Mii Maker on your 3DS and select Send/Receive. Then select Mii Channel (Wii) and the 3DS will begin a search. Now on your Wii, go to the Mii Channel and select the Connect to DS option on the bottom right of the screen. If it doesn't appear enter, A, B, then 1 and oress and hold 2 for several seconds until the option appears. I don't know why that's even a thing, but it is. Next, select it. On your 3DS, you'll be asked to select which Wii to connect to, so obviously pick the only choice (Unless you live in a house full of Wiis
) After the systems have agreed to communicate, you can simply pick up any Miis that you'd like to copy from the Wii and drag them into the box that has appeared on your screen. You can only copy one Mii at a time, but it's a quick process. You'll be asked to confirm the transfer after it's finished on your 3DS. Just a note, this process copies the Mii from your Wii. You will not lose it on your Wii when you send it to your 3DS.
Hope that helps!
