Just be careful that you’re both designating each other as a beneficiary on any insurance, 401K/other retirement vehicles, or other assets (stocks, bonds, housing, accounts etc). If she’s not legally your spouse, she’s not going to be automatically entitled to any assets if she’s widowed or vice versa.

You both may also want to have a will or power of attorney clause given to each other in case of medical issues which prevent someone from communicating their own will. Family members get the right to act on behalf of their family, but they can’t do anything to help or protect if they’re not legally related in some way. Some places have clauses for common law spouses, but not all do, and not for all circumstances.

Does that not hurt you on your taxes/government forms? For instance, for a period of time, my wife was making far less than me and that helped us with our taxes by giving us deductions since our combined income was under a certain threshold. I believe it helps with other things as well.

Just trying to call you out, just curious because I saw this as a net benefit overall.