Yes, E-filing is an option for someone filing under the authority of a Power of Attorney.
Prepare and file the return as if you were the taxpayer.
Then, complete and send Form 8453 with Form 2848* to the IRS within 3 business days after your e-file is accepted.
(*Or other POA stating you have authority to file the tax return)
Check Block 2 (Form 2848, Power of Attorney and Declaration of Representative (or POA that states the agent is granted authority to sign the return)
Mail Form 8453 to:
Internal Revenue Service
Attn: Shipping and Receiving, 0254 Receipt and Control Branch
Austin, TX 73344-0254
