My advice is that your parents return it to the LFS that they got it from and demand their money back or at least get a trade for an anemone that doesn't already have a huge strike against it.
If your anemone won't anchor, there isn't a lot you can do except to provide it with the best possible lighting and water parameters and watch and wait.
How old are your bulbs? Bulbs need to be changed regularly, and if they're old bulbs it may be affecting your anemones happiness. Unlike BTA's the LTA's naturally occur in the sand, so they won't climb higher to get to better lighting.
It should be sticky at this point. It should be happy with the silversides and shouldn't require additional soakings of anything for the silversides. I took in a stressed, starving, underlighted and bleached LTA and it was eating like a champ within two days and regained most of its color in a month. It's under a 4x96 PC Custom Sea Life lighting set up.
I'm totally serious about taking it back if it was already stressed and still isn't eating well or attaching.