My kid is afraid of

Santa clause, the Easter bunny, the tooth fairy and every other make believe being. I have 3 kids and my other 2 are just fine. But my middle kid is completely freaked out! She asks questions like how does he get it, why is he in our house, is he breaking in, why are the afraid to be seen. She just lost a tooth and I'm not sure what to tell her. She said she doesn't want the tooth fairy coming.  I can't tell her they aren't real because my other kids will find out. She's been upset all day over this. This Easter I had wrote a note to her from the Easter bunny, saying he loves her and all of these nice things.... She cried. What do I do? Ruin it for the rest of the kids?