No. He is her spouse and a derivative on her petition regardless of whose money is used. His contribution is documented as a gift to her, with his own source traced, or the couple's joint funds are explained as such; only one of them is the principal investor.
One principal, one petition, and a documented gift for the spouse's share
An EB-5 petition has a single principal investor, and her spouse and unmarried children under 21 obtain conditional permanent residence as derivatives. There is no advantage in making the husband a second petitioner for the same investment, and the regulations do not treat a married couple as a joint investor. Where his half of the house proceeds forms part of the capital, the file must show that the funds became hers before or at the time of investment.
The usual method is a gift letter from him, the bank transfer from his account or the joint account into her name, and a trace of his own lawful source for those funds — the same house-sale documents, since the proceeds are shared, plus his income history if needed. Funds in a joint account can be explained as jointly held with the other holder's consent to their use. The children's ages should be checked against the filing date, with the Child Status Protection Act freezing a child's age while the petition is pending.
If the husband is not a Canadian citizen, his own admissibility is examined at the visa stage on his own facts.