Daycare or Grandma

FTM here with a 19 month old. We started gradual entry with our daycare, and she goes to daycare 2 days a week after that as there was no full time spot for her. Since it was 2 days only, it’s harder for her to adjust to daycare routine.

We recently just got a full time spot for her. She was doing great during her first full time week, and I can see her starting getting used to the environment and routine. Unfortunately she got sick after the first 1.5 weeks of full time daycare, until now we have already kept her home for a week. My husband is thinking pulling her out of daycare because she’s been sick too many times and it’s not helping her development (because she’s always been sick).

Both my husband and I work full time. We have flexible schedules but our hours is still 40+ hr/week. MIL is willing to look after her, which I am very grateful for. However, she does not take her out - not even to the park or playground. We had MIL come over to look after our daughter when our daughter only goes to daycare part time. MIL only stays at home with my daughter. I set up play area for my daughter, and I rotate toys for her. But that’s it. She also doesn’t let my daughter walk fast (telling her that she would fall), doesn’t let her climb onto the couch sofa, gets terrified before my daughter does when my daughter actually falls. I know my daughter will be safe and healthy with my MIL, and I know my MIL loves my daughter so much that she doesn’t want her to be hurt or get sick. But I still feel this is not right.

My daughter seems to be a very introverted person. She gets scared when other bigger kids are running fast/shouting screaming around her. She does observe other kids sometimes but doesn’t approach them every time. When we are out during the weekends, it always takes her some time to adjust to a new environment (such as new parks, new shops, etc) and if there’s too many people around (adults or kids), she would get upset and wants me to pick her up. Her stranger danger is still at the peak. She cries when strangers come up to her. Although she seems to be better if the stranger is a woman.

Sorry it’s a bit all over the place but I guess my questions are - should I keep sending her to daycare when I know she will get sick a lot? Or should I let my MIL look after her (or at least 3 days a week)? Is it actually fine that she gets zero socialization during the weekdays but only on the weekends?

Also is it normal for a 19 month old be so scared of strangers and sometimes other toddlers? Will it get better..and what did you do to help your LO outgrow this stage?

Thanks a lot!

Edits: typos.