Ppf doubts regarding

Ye You can claim money on ppf deposited in your wife name for 80 c deduction .no need to show income proof for claiming the deduction but the only point is she should not claim deduction in her return of income 

80C. ⁶¹ (1) In computing the total income of an assessee, being an individual or a Hindu undivided family, there shall be deducted, in accordance with and subject to the provisions of this section, the whole of the amount paid or deposited in the previous year, being the aggregate of the sums referred to in sub-section (2), as does not exceed one lakh rupees.

(2) The sums referred to in sub-section (1) shall be any sums paid or deposited in the previous year by the assessee—

          (v)  as a contribution to any provident fund set up by the Central Government and notified ⁶² by it in this behalf in the Official Gazette, where such contribution is to an account standing in the name of any person specified in sub-section (4);

(4) The persons referred to in sub-section (2) shall be the following, namely:—

          (a)  for the purposes of clauses (i), (v), (x) and (xi) of that sub-section,—

       (i)  in the case of an individual, the individual, the wife or husband and any child of such individual, and

      (ii)  in the case of a Hindu undivided family, any member thereof;

Above is the relevant portion of Section80C for your perusal, As per sec 80C(2)(v) the contribution can be made in the name of person specified in Sec 80C(4) and 80C(4)(a)(i) says that wife is included in the defintion of person.

In your case deduction is admissible, if you made contribution to PPF in your wife's name. Coming to the second part of your question regarding proof of payment, Firstly Nowadays system of self assessment is followed, secondly in case of e-filing there is no such requirement for submission of proof.

But you must keep record of such payment, in case AO feels otherwise he may call for information and records

Hope this will solve your purpose.