I think she have this mental illness called crush fetish
A crush fetish is a paraphilia which primarily consists of the
desire to see others (generally members of the opposite sex) crush
small creatures such as insects, mammals and reptiles. Inanimate
objects, such as cigarettes, fruit or toy cars, can also be crush
fetish stimuli. The term "crush fetishist" also refers to those who
perform the crushing.
This sexual fetish is popular amongst many foot fetishists[citation
needed], as crushing by feet is usually the main focus (although
other methods are implemented, such as sitting on the target
object). The foot (barefoot or in shoes) is thus often idolised in
crush erotica such as magazines, audio tapes and crush films.
Taken from wiki pedia: read more there
http://en.wikipedia.org/wiki/Crush_fetish#Crush_films
To trample generally means to crush underfoot. Stampeding animals
often cause injury to people by trampling them. During the Middle
Ages, horses were sometimes trained to trample opposing
soldiers.
In the card game Magic: The Gathering, trample is a common ability
given to creatures allowing the creature to deal the remainder of
their damage to the opponent after blockers receive lethal
damage.
Trampling may also have a sexual connotation, especially when in
relation to BDSM. It involves the act of the dominant stepping on
and walking all over the submissive. This can be done sensually and
barefoot, or more to cause pain with high heels or boots or other
shoes. The psychology behind it is that the submissive is
"underfoot" the dominant, and is below him/her (literally and
figuratively).
Taken from:
http://en.wikipedia.org/wiki/Trampling
meaning crushing stuff will make someone genital arouse if he/she
have this mental illness.. i dunno got cure or not lea