بسم الله الرحمن الرحيم
You are not allowed to purchase and donate carpet to Shia mosque or Imam Bara. It should be noted that when your wife became Sunni Muslim, then should leave Shia practices and become –Sunni Muslim completely.
Allah knows Best!
Darul Uloom Deoband
This answer was collected from the official ifta website of Darul Uloom Deoband in India.