Advice re OAP dog. Change of smell?

[mzzzf]

Hello

Maybe a bit of an odd one but my brain is doing circles over this. I have an 11.5yr old mastiff pointer cross bitch, who is awesome. We lost her sister last year and since then she’s been a bit less spunky/more chilled out (sister was runt).
But something odd has been happening on our dog walks, literally every dog recently (last fortnight) wants to sniff her, challenge her or try and mount her. What is going on?
She’s had no change to her diet or lifestyle in anyway and was done a decade ago. She is an alpha dog but certainly doesn’t posture out on walks etc. My brain is going in circles because for the few weeks before her sister died, she really smelt (cancer by-products) and I’m just wondering if it’s happening again or if there is some other explanation for why every other dog is so interested now....
Any insight would be brilliant!