Solo 401(k) question
My wife is in the process of switching careers and is working for one place that withholds taxes and has a 401(k) plan in which she participates and in another where she is an independent contractor where she is paid an hourly rate with no taxes withheld. She's received a 1099-MISC for her income as an independent contractor. She contributes to the 401(k) but finished the 2017 tax year well below the maximum contribution limits.
My questions are (1) whether it's permissible to have a 401(k) and a solo 401(K) with contributions in the same tax year, provided those contributions combined remained below the 2017 limits and (2) if I opened a solo 401(k) account for her in 2018 for the 2017 tax year prior to submitting my tax return, would I be able to fund it with pre-tax dollars (i.e., even though she earned the money last year, would I be able to subtract the amount contributed in 2018 from the amount listed on her 2017 1099-MISC form)?