Question from HEG
This is not a question, but rather an answer to anyone who may be searching for a glass sippy cup for toddlers (as I have been for two years). I just learned that the company Lifefactory makes glass sippy cups/toddler bottles with silicone sleeves to protect them. They also make similar water bottles for adults.
Another option is the Bornfree brand, but for this you have to be a bit more creative. Bornfree makes glass baby bottles and plastic toddler sippy cups and recently added silicone sleeves for their glass bottles. The parts are interchangeable so you can take the glass baby bottle with silicone sleeve and simply put the top/spout from the otherwise plastic toddler sippy cup on the glass bottle (and just get rid of the bottom part of the plastic sippy cup).
Hope this information may be helpful for other moms of toddlers out there!