i'm not sure any small lily can handle sliders--It been my experience that one of their favorite things to do is snip the lily leaves off of lillies-and those little lillies can't take too much of that....You know if she wants something with floating leaves maybe try a snow flake...they can be snipped and still grow like mad because thats how they multiply....also hornwort or anacharis as a sub would be good...
Lawanna