Do not give your pregnant Maltese any extra calcium (food or supplements). Increased calcium during pregnancy (excluding right before labor) has been connected with eclampsia, more difficult labor, and both calcium deposits and certain joint abnormalities with newborns puppies.
Keep her exercising
as normal to maintain muscle and endurance which will help her with whelping.
Limit jumping. You may want to obtain pet steps or ramps to place against sofas or chairs.
Nesting instincts will be strong; if your Maltese does not have her own bed, now is the time for her to have one.
Keep other dogs in the house away from her if she seems troubled by them. And, if the sire is present in the house, he should be segregated away from her by Week 5. Also, do not allow him access to her during delivery and do not allow him access to the newborns until they are at least 4 weeks old.
Do not use any flea or tick treatment on her without vet approval.
By Week 4, the veterinarian may recommend a switch to puppy food to offer a diet higher in fat.
As you get closer to the expected whelping time (Week 6 or 7), speak to the vet about starting to offer calcium-rich foods such as whole cottage cheese (do not give this earlier in the pregnancy, and do not add this at this time without vet approval).
The sign that a Maltese will be ready to give birth will be a drop in body temperature. Therefore, her temperature should be read daily starting on Day 57. By Day 60, this should be done twice per day. When it drops from its normal 101 and 102.5° Fahrenheit (38.3 to 39.17 Celsius) to below 100° F (37.77 C), she should deliver her litter within 24 hours.