3.5 month pups

Question
Hi, we have 2 from the same litter at 3.5 months, doing well, good girls.  My question is whether replacement mother's milk is good for this age and beyond? They haven't had it for a while, as I did not know if I should continue.  Or is there a supplement needed in addition to food and water?  They have iams smart puppy formula food.  Thanks for volunteering your time.

Answer
I have a great, inexpensive homemade formula:

I an blender:

1 can evaporated milk (not condensed and generic brands okay)

1 cup plain, whole yogurt (no flavors; generic brands okay, and plain yogurt is a great treat by itself, especially in summer when hot outside)

1 teaspoon white syrup (like Kayro syrup; generics are fine)

Blend (not froth)

Pour into container with sealed lid and add 10 ounces water to mixture and keep refrigerated.

You can pour into bowl for them to drink if they are drinking from bowls safely.