Secret conversations...

Im curious as to whether or not someone has to actually be using secret conversations on their device for it to show their devive in the secret conversations tab. I ask because my girlfriend claims to have never used secret conversations but everytine i got to privacy and select secret conversations her phone along with several other ones are there. I even remove them everytine to go back and look and boom there they are again. Thanks in advance for any info u can give me on this.

System Configuration: Android / Chrome 89.0.4389.105