DF's mom is a doula and she is extremely pushy on everything and she's not even my doula! I do not have one nor do I want one. I'm sure not all are doulas are like her, I think it's more of her being this way because it's her grandchild. she pushes me to do it her way. for example I am not breastfeeding and she still asks me if I am which by the way is none of her business and I telll her no just as I have before and she pushes it on me and then tells me "if you have any questions ask me" even if I did she'd be the last person I'd ask.
she constantly tells me how doctors aren't completely necessary and she'll say aggressively "birth is NOT a medical condition" I understand she wants to think that way but if something went wrong during birth and I wasn't in a hospital and it affected my baby in any way I would never forgive myself for having listened to her. she tells me stories of how some client of hers stayed at home, took a bath and relaxed after her water broke and when she decided to go to the hospital she had the baby within the hour and due to all the relaxation she labored at home and didn't even know it! as amazing as that sounds my family has had issues. my sister's first baby's umbilical cord wrapped around the neck, the baby didn't make it :( . friend of the family, the baby's heart rate dropped dramatically and they had to do an emergency c-section so luckily she was at the hospital. I plan on going to the hospital at the first sign of labor and DF's mom has a problem with that but idc.
My vote is for no doula OR if you decide on having a doula, interview her. make sure she knows where you stand. she is there to ASSIST you, not to push her ways on you. like I said, I'm sure they aren't all like DF's mom so my answer is just based off my experience from being around her so sorry that my answer is biased.