She should not be worried unless he doesn't stand, our hold himself up on things. all kids move at different paces and some even miss their milestones and still turn out ok and normal.after 20 months, which is late, she should check more thoroughly with doctors but that still doesn't mean anything is wrong.
Yeah he does hold to things but he gets stubborn when shs tries to encourage him.
If he's standing on his own then he's probably just afraid to take the first step, he's probably fine. All babies start walking at different times. If she's worried though she needs to speak to her pediatrician about it.
All my kids but one started walking around 15-17 months. Is he standing or taking steps? Some kids just take longer than others.
Has she asked her sons pediatrician about it.? I know when I took my son for his first year exam she asked a big list of questions about milestones and on that list was walking and/or "cruising" which is grabbing hold of couches or something to walk. My son started at 9 months but every kid is different. Does her son at least try to stand up.? I would only be concerned if he isn't grabbing hold of things and trying.