@CSMontag first of all, welcome to the forum where you will find answers to most any question you could think of regarding petsitting. This group has some amazing experience (and experiences) they can share with you to help your journey be even more incredible!
The first thing I would do is link is forum profile to your member profile so other THS members can easily find you and help give you valuable feedback on your listing. To do so, just click here at How to add a listing or profile link to your FORUM profile - Welcome & Getting Started - TrustedHousesitters Community Forum and follow the easy instructions.
Now, my answer to your question would be no. There is never a reason to need to tip your sitter as this is a mutual exchange between sitters and pet parents. Pet parents are getting someone in their home to care for their pets and watch their home while they are away, and sitters get the opportunity to experience new locations, but most importantly, love on some awesome furballs!
Many pet parents do tip their sitter but I find that leaving a gift basket filled with treats to get them through the evening and breakfast the next morning, as well as pamphlets on local attractions, pubs, shopping, etc. are more appreciated. This way they aren’t throwing down their bags and heading to the store for meal prep instead of getting to know your pet(s) as they should. Personal preference to me, and others have a different opinion but it has always worked in my situation with more than 20 sitters in my home during the time we still had our little girl.
I am sure you are going to get various opinions and ideas, and really, all are good, but just remember, no fees can be paid to a sitter for their services.
Enjoy your new adventures that are awaiting you!