I’d talk to her and find out if it’s something she’s interested in doing. If you guys shop on LH together, maybe try browsing anal toys together to see how she reacts to it. Definitely start with fingering/butt plugs/beads before jumping into anal sex.
Is there a reason you guys stopped anal play before? We had anal sex a few times early in our marriage, then I had a bad experience and didn’t want him touching my ass for many years, so then, when I was interested in doing some anal play again a decade later, I was really embarrassed to admit it. Communication is key, but if your wife had a bad anal experience, it might be a hard conversation to initiate
If you want to take the initiative without talking about it first, I would not recommend just sticking a finger in! Might be ok for some, but for others it might make it a permanent turn off… Take it slow and maybe try just rubbing outside the hole with a lubed finger during foreplay and piv sex for a few sessions. If she doesn’t hate it, maybe during the next couple sessions, when she’s feeling good, press in just the tip of your finger - that alone can feel good because of all the nerve endings right there After doing some of this, it should be a bit easier to bring up anal play in conversation to see if she’s down to do more (anal toys and anal sex) - this is how it went with my husband and I