Since I gave birth to my third baby, I have felt very "slack" down below. This is having a bad effect on my relationship with my partner because both of us feel my vagina is now much too loose. Any ideas?

You need to start immediately on some "pelvic floor exercises", and practise them several times a day for at least six months. They tone up the muscles round the vagina. Any midwife or physio can show you how to do them. If the exercises don't do the trick, then you'd need to see a gynaecologist to discuss the possibility of a repair operation. Also, as a purely temporary measure, you will find things feel better if, just before making love, you slip a tiny vibrator inside and keep it there throughout.