Financial advice needed for a near 40 year old

I’m 38 and my husband is 40. I take home around $4500 , whilst my husband around $5800, both after cpf deductions. Staying in a 5 room hdb resale flat. We have 2 kids, one 3 years old and one 10 months old. My husband takes care of the childcare fees , enrichment classes, utilities bills and kids insurance.

Below is my monthly spendings:

1. Stocks and savings plan: $800

2. Allowance for my own Parents: $1400 ($700 each parent)

3. Insurance: $100

4. Internet and phone bills: $100

My credit card bills racks up to between $1500-$2000 or over per month, making me unable to save up anything or even eat into my savings. The bills include transport fees, eating out, groceries, buying toys , clothes for the whole family.

My husband and I do not have any joint account, we keep our finances separate. Until now I have in total about $100k worth of assets and savings (including the stocks and savings plan worth), but only $15k is available as immediate emergency funds.

I know I am very blessed already with a job and a roof over my head. Cutting down on the allowance for my parents is a big no as they are both not working and I’m the main pillar of their source of income. But I would like to know by the age of 40, what is a healthy amount of savings one should have? Any advice on how do one increase their savings, especially being the sandwich generation.

Thank you for your time reading this! Have a great day ahead.