My daughter asked me this today and i laughed is this wrong?

she was outside on the phone with me and she asked why do think you can marry a boy who never leaves you.now she 4 and i didn't really understand till i talked with my sister liz. and she had told me the kids where playing like someone was getting married and i guess mya was with a boy who never left her side,. kinda of cute i got emails even of of the kiss.....my baby ain't little anymore! but i laughed when i talked to her and again she goes do you think this is funny mommy. was i wrong to laugh?