I would strongly advice checking with a doctor before taking any medicine you are unsure about (some things are best avoided when pregnant and then breastfeeding).
Please check with the doc, it delay surgery what is the consequences? Or will affect any of her knee pain? Also do let the doc know that you are pregnant may have to wait till labour. Because you need a hand to tc nb n mom after surgery . Ask for best option & advise. Any meditation given can ease the pain at the moment? Have your Mom done MRI scan? to ensure that there are no torn tissues or ligament. If there is, TCM may gonna worsen it. I think gather all the info from the doc first. Maybe you can check with TCM just give medicine will it help for the pain if doc didn’t prescribe any My mil had Arthritis, she went surgery in 2016 or 2017 Rem to get a support & comfy shoe first Do check your mom has any insurance covered?
Rae