Vanessa is the best host you can wish for.
She is warm, welcoming, punctual, helpful and full of information about any attraction you can possibly be interested in.
Her studio is tiny but comfortable and squeaky clean.
There are couple things you should know: there's no storage for your stuff, as place is so tiny, and be aware of very steep stairs.
This is what you need to consider if you want to stay in the heart of Alfama - oldest part of Lisbon.