The usage of Ash's fear-based technique could be used to circulate the Life Energy through her body and the foreign Life Energy would be swept up and mixed into her own.
No trace of the foreign Life Energy would be left on its own after all of it had been swallowed up with her own.
It would be like a small amount of a liquid getting swept up within a much larger amount and then follow the flow of that liquid becoming one with it.
Such a process would be greatly helpful toward her being able to absorb the foreign Life Energy a little bit faster since the integration process would be sped up a little more and any lingering energies in her body would no longer be as spread out and out of her control.
All of that swept-up Life Energy would be gathered and would be sent toward her eyes along with her own Life Energy a little at a time but since there was no target to use her technique on, the Life Energy would soon return to its cycle through her body again.