I let my moms and pups decide that. I've had mine nurse (probably just for security) for up to ten weeks. The pups are eating well, but the mom will seek them out for a quick bonding time together. I've had two moms do this in the last two years. I feed my moms puppy kibble while they are nursing, so it's common to just see the pups crawl up in the bowl with the mom. One thing I learned from my mentor is that if the pup starts getting red tint to the hair around its mouth, it is not getting enough milk. I have a five and one half week singleton that this happened to this week. Mom is also showing red hair on her tummy. I was advised to do special feeding for him (baby rice cereal, meat, and a little pudding) so that I can make sure he is getting enough. Both he and mom are pudgy, but I'm doing it just to be safe. They are in my bathroom, and I noticed he was nursing a few minutes ago. Again, it's a security thing in part.
Maltese are slower in weening than some of the larger breeds.
Also, I've found that the most curcial time with the Maltese pups is around eight weeks. It's like they "forget" to eat. I have had them doing well, then have a sugar low at this age. I don't separate my pups from their mom until at least ten weeks of age. I don't want them stressed in any way.
It depends on how tolerant the mom is. I always let the pups nurse as long as they want as long as there arent any special cercomstances. By 6 weeks of age they're eating 4 times a day and nursing very little. My girls will usually give them a security nurse once in a while up to 10 weeks or so but not very often.
I agree with the rest I let the mother tell me. When they start cutting teeth I soak puppy food and let them have that several times a day. Prissy will let them nurse until she is tired of it. I remember last summer when she had 5. When they were about 8 weeks I kept them in the breakfast nook in a play pen. Prissy would want in there with them but in 5 min she was trying to climb out. They would tackle her she had no choice to give in. It was cute to watch. I have also noticed as prissys baby is getting older she is producing less milk. Still plenty to feed him, shes just not as full. That is a neat trick about the red around the teat and mouth. I have never heard that. I just thought it was like a tearstain issue. Prissy has never had this but I have seen this with other Females. I love this Site you learn something new everyday.
Oh I also hope people dont judge me poorly because I'm too busy to go back and fix all my typos. I really dont have the time, I'm sure yall can tell what I mean