My pregnant sister has swollen feet and she is in 3rd trimester, how can i help her?

Your sister can - drink more water (prevents the kidneys from thinking that the body is dehydrated and also helps to flush the salt out) - elevate her feet (by resting them on a higher stool) when resting - place a couple of pillows under her feet when sleeping to keep feet elevated - limit her caffeine intake (caffeine is diuretic and also causes dehydration, which will cause the kidney to retain fluid) - limit her salt intake - exercise and keep active I suppose you can help by reminding her to drink more water, elevate her feet, cooking healthy meals (with less salt) and go for walks with her. Great sister bonding opportunities too!