Appropriate for Pastor's Spouse to Serve on the Board of Deacons?

Church Order is a wonderful resource, but it often does not cover every nuance in ministry.  That being said, many church Council's establish policies along with Bylaws that indicate if family members can serve together.  It might be good to check to see if you particular church has policies in place.  If not, perhaps this is a good time to establish them.  Now as to the Pastor's wife serving on the board of deacons - again it all depends on if that particular church recognizes women serving on Council.  A pastor's wife may have the heart of serving, and her being a deacon would greatly enhance the ministry of the church.  

When serving on boards in Canada see: https://www.canada.ca/en/revenue-agency/services/tax/technical-information/income-tax/income-tax-folios-index/series-1-individuals/series-1-individuals/income-tax-folio-s1-f5-c1-related-persons-dealing-arms-length.html 

If a pastor's wife served on the Board of Deacons and if that board was also part of that church's council, the pastor's wife would part of the body overseeing, among other things, the church's budget. The pastor is accountable to council; the pastor's wife would have oversight over the pastor. Probably not a good thing.

If there is a clear separation between the work of deacons and their role within a church council, to the point that there would be no conflict of interest -- perceived or otherwise -- then that might work.

In one of the churches I served as a pastor, there was a rule that spouses could not serve on council at the same time.   When the council realized that my wife would never be allowed to serve with that policy in place,  the council made an exception for her.  She is a very gifted person and not only was she delighted to serve, but the church was well served.    She would simply abstain from voting when needed.   Another church made the rule that spouses not only could serve, but allowed a husband and wife to serve as deacons together.  They were each gifted deacons and they enjoyed the activity together.  They also enjoyed not being deacons together, rather than one of them almost always in office.   This worked out very well.  We never felt there was a voting block or abuse of power.   We trusted each other and made our points.  Sometimes they agreed and sometimes they did not.