Based on threads on this topic previously, the chance is so rare - the lady approaches you - that none of us worry about it.
What has been reported to happen is idiot clients approach a SP they have seen, while she is with others (family, boyfriend, her kids, etc) and the horror stories of these events has been shared before - excited idiots attempting to be publicly affectionate with the lady with total disregard/disrespect for the industry he met her in as a real worse case example.
At most you may get eye contact and a smile from a lady you have seen before is the experience most of us (who have been through this) and then if you pause and make yourself available she may (or may not) approach you. So to answer your question if you see a SP you have been with in public and have any worries, just avoid eye contact and carry on.
The last lady I saw in public (mall) that I knew fairly well as a Indy SP - after she saw I was walking alone through the mall - text me to say hello. I replied with an offer to meet in the food court for a coffee which she agreed to. Other SP's I have seen out with their girlfriends (again usually at the mall funny enough as I look back) will glance over and I make sure not to smile or give away anything - walk right by - makes for a good laugh when you see her at work the next time if you choose to.