How much should a 35 year old woman weigh that is 5'5?

Around 60kg is healthy.

A BMI is a thing to work out if you are underweight, healthy, overweight or obese. Some people are tall and because they are tall they are heavy but they are not overweight.

To work out your BMI, you get your weight in kilograms, divided by your height in metres, squared.

So,

5'5 is about 1.65 metres.

1.65 x 1.65 = about 2.7.

60 divided by 2.7 is a BMI of about 22.

If your BMI is less than 18, you are underweight. If it's 18 to 25, it's healthy. 25 to 30 is overweight and over 30 is obese.