Have not heard of any problems with implants. Her LHR Tech or Nurse should be able to answer that question. The amount of energy used will not penetrate past the Dermis layer. LHR works by heating the hair folicle, thereby destroying the blood vessels supplying blood and hormones to the hair. LHR works only on dark hairs. Shouldn't be any problems.
SJ
P.S. Padma got there first, but brought a good point about allowing the incisions to heal first. Ask your friend to hold off until the LHR is done, probably 6-8 months. Large implants may make the task more difficult if there is a lot of hair.