Your sister cannot do an E bar dismount in Level 9 because she would either incur a mandatory deduction for omitting a bar change or void part of the routine for performing two D or more elements. Also, blind bar landings can be very dangerous for young athletes.
Gymnasts nearly always learn pike yurchenkos much easier than layouts because pikes use heel drive. I've never seen the reverse. Except for extremely powerful young athletes who understand shapes, usually pike yurchenko score better at L9 because of the fewer shape deductions. Even McKayla Maroney competed a pike yurchenko at L9. She won westerns with that vault.
Gymnasts nearly always learn pike yurchenkos much easier than layouts because pikes use heel drive. I've never seen the reverse. Except for extremely powerful young athletes who understand shapes, usually pike yurchenko score better at L9 because of the fewer shape deductions. Even McKayla Maroney competed a pike yurchenko at L9. She won westerns with that vault.