tappar can mean 'drops' as in 'it fell out of her hands' or 'loses', you can't be sure.
If you add bort and say tappar bort instead, it will be unambiguous (and mean like 'misplaces').
förlorar is the only one used for e.g. losing money in a game. It can't be used for the physical act of dropping something (as in when it accidentally falls out of your hands), but it can be used when you lose something as in you don't have it anymore. Hope this helps!
Just like any other language, it is all about context. 'Hon tappar sin telefon' can mean both 'she drops her phone' and 'she loses her phone', but only context will reveal the true meaning. However, you can add 'bort' after 'tappar' to avoid ambiguity. 'Att tappa bort' means "to lose" (as in to misplace something).