A while ago, I was visiting an acquaintance to help her with something. After I finished fixing the problem, she asked me to do another thing "while you're at it". Let's say I'm done sweeping the house, and she asked me to mop the floor. The task was related, and it would take approximately half an hour.
This was not something I've agreed to do before, and certainly I was not planning for it. The complexity and needed time of the issue were not an issue (although it was not a small task), I didn't have anything else planned, but I felt like I was put on the spot if I refuse.
Additionally, from the past interaction with this person, I had a suspicion that she was planning to ask for this when she asked for my help. Note that I'm also worried that her request become slippery slope.
After this, can you do X? (After I've done X) Can you do Y? It will only take 5 minutes, I promise!
How can I refuse her request politely? My goal is to refuse the task and maintain the relationship, especially allowing me to leave (preferably not immediately, see below) with smiles on both of our faces :)
I was visiting her to improve relationship. That's why I agreed to help her in the first place. Refusing seems to nullify what the improvement I was originally aimed for. Preferably, I was hoping to stay a while for a chat (casual, but I have certain goal in mind), but if it's too awkward to stay after refusing her request, I'm fine to leave. (for example: I need to go)
Update: Initially I was asked to help her install a software. It took an hour to get the software ready for her to use. After that, she asked me to install the companion app on her phone. I could see that I have to check whether the app and the software in PC can communicate with each other properly.
I doubt there's a "professional" that I can direct her to, because the task seemed very simple to be handled by a technician. She lived alone, so she had rather limited connection to someone who can do this. I can understand that.