Change in job duties

Hey All, new to the thread, but just looking for some advice on how to handle a situation with my family.

Just a little bit of background, I work for a UHNW Family and have an amazing relationship with them and absolutely love my job caring for their one year-old. They are both under 40 (as am I) and are not super experienced with having household staff/the expectations, etc. but they have had a house manager for about four years and I have worked for them for nine months. I work 40 hours a week, but have 10 weeks of time off built into my contract because they do a lot of traveling. I make $40 an hour and they compensate me a bit for my travel so my total salary works out to 88k/yr. They also provide any meals I want while working. My agreement includes childcare only but I also do some cleaning here and there in between when their cleaners come.

They have had a house manager for about four years. I don’t know what her salary was, but I know that she was working full-time. (Although they are pretty sure she was padding her hours) They have also had a prep chef who I’m not sure how many hours a week he worked, but I know they paid him around 150 an hour which is wild. 😆 but he moved.

About three months ago, their house manager was let go and they asked me if I would temporarily take over keeping all their groceries and household items stocked. While they looked for another manager. It has definitely added quite a bit of mental load, but isn’t hard by any means and I’m able to do most of it while with the baby or take him shopping on trips out. It was supposed to be temporary but a few days ago they let me know that they have decided to pause on hiring a house manager for now since everything has been going fine and it seems like she wasn’t doing much anyway.

I have done a bit of meal prep in the past, but it has mostly been for the baby and during the same discussion they asked if I would be willing to prep 3 to 4 meals per week for the The family/baby. I am happy to do this as I love cooking, but once again it’s an added responsibility to plan/shop/prepare meals, etc. The baby is getting a lot busier and is almost walking so most of my meal prep time will probably be during his two hour nap which is typically the only time I get a break during my 10 hour workday.

So now onto my question/advice from everyone! They haven’t ever mentioned a pay increase and initially I wasn’t planning on asking for one. However, I have a tendency to undersell myself and just be amicable and say oh yeah sure I’m happy to help with that! But now that I am taking on the roles of part-time chef and part-time house manager I’m thinking I’m going to ask them for a pay increase. I would love some advice on how to go about this, how much do you think would be appropriate to ask for, etc. Any other advice would be welcomed!

I think my biggest problem is that I do feel very well compensated and don’t want them to feel that I am ungrateful for what I am paid currently. I don’t think they’ll be upset by any means but I just want to feel that I am compensated fairly with these added responsibilities.