Some species live off of the dead roots and leaves of the grass itself. Of these, the only ones that actually damage the lawn are the various "fairy ring" types. For the others, if there are young children or dumb dogs involved, an early morning toadstool patrol is in order, since most kinds are poisonous, and it takes an expert to be sure of the edible ones. Fairy rings, which leave a ring of dead grass, are a little more difficult to deal with.
In my experience, mushrooms of all sorts can be reduced by increasing the diversity of the soil flora, usually done by spreading a thin layer of sifted living compost--not potting compost--on the lawn twice a year.

They come in from microscopic spores blowing in the wind. You can't ever get rid of them permanently

As Bathgate says you can't get rid of them permanently. The fungi your daughter is seeing is simply the fruiting body of the mycelium and, no matter what you do, getting rid of it isn't an option, sorry.

Sorry, Redwine, I should have made that point first. All you can do is give the mycelium competition, as I said. That will result in fewer mushrooms, but not none.

If they are small ones you can just brush them off with a stiff brush when they appear if you don't like them. If they are large ones you can pick them off and dispose of them. If you cannot identify them you might like to use gloves when you do this - not many of the ones likely to be in your lawn are poisonous though. Have to confess i like them.

I really don't think they are worth the bother. They don't hurt anything & they disappear once the sun hits them or the ground dries out a little.

Exactly Bathgate...

I absolutely love finding fungi in my garden; they fascinate me. My best fungi experience was discovering two puffballs but sadly I haven't seen them since. Nevertheless, Redwine, if your daughter hates them, it's not good news for you that they are virtually inpossible to eradicate for good.