++ Moms don't deliberately make their children overweight, of course; and a lot of factors contribute to weight problems. However, medical advice given in the 1950s and 1960s could be adding to the "obesity epidemic" we are seeing now. That advice is now considered obsolete, but could still be causing trouble.
Epigenetics is a study of how environmental cues can affect how genes are expressed. One aspect of it that is being investigated now is this: If a person is poorly nourished before birth, how will the body try to compensate, and what does this mean for weight and health issues later in life? One researcher in this topic, Melinda Southern of Louisiana State University, refers to the out-dated advice mentioned above as "the obesity trinity." The trinity:
1) Pregnant women were urged to gain less than 20 pounds during pregnancy; some doctors said only 10 lb. There were a variety of reasons for this: babies would be smaller and easier to deliver with forceps, mom would get back her pre-pregnancy weight sooner, etc. (A normal-weight woman now would be advised to gain 30-35 lb.)
2) Many women were told to smoke up to a pack/day to help them reduce the weight gain. (Since then, we've learned of dozens of reasons NOT to smoke.)
3) Bottle-feeding is the modern way, breastfeeding is passe. Or, so it was said. (Now I could do a whole long post of nothing but a list of ways breastfeeding benefits both mom and baby.)
Directly or indirectly, 2 of these have a negative impact on the baby's growth and development in the womb. Breastfeeding, of course, makes it's biggest impact in the early months after the baby is delivered. Back in the day, breastfeeding one child often impacted the growth of the next one. Reliable contraceptives were rare. Breastfeeding a baby exclusively (no formula or baby food) delays the return of the mother's periods/fertility. In spite of the nutrients going to the baby, it gives the mother's body more time to recoup from the pregnancy. Without breastfeeding, the next baby came sooner and had a smaller nutrient store (in mom's body) to draw from.
If a baby's growth is restricted during this critical time, it appears that he/she will be programed to be less sensitive to hunger/satiety (fullness) cues and to hormones like insulin. This makes it easier to gain weight - an advantage in the Stone Age, perhaps; but not here and now, when food is easier to come by and "labor saving" devices allow us to get by with burning off fewer calories.
bottom line: For you: Don't get angry with Mom - she did the best she could with the advice that was current then. You can still stay at a healthy weight; it will just take a little more work.
For your children (and possibly, your grandchildren): Start to form good health and dietary habits right now, if you haven't already. You want your body in good shape before pregnancy, and to maintain that during pregnancy. Then, breastfeed. Men: this includes you. Healthy sperm contributes to healthy babies; moral support for the pregnant woman in your life contributes to healthy relationships.