Home Rental In Los Angeles

[Marta Paglianni]

Any tip is welcome. 

I  rented my home to a young couple 4 years ago with one dog. And now they have 3 dogs, 1 cats and 2 small girls. When the lease was done and signed it was for only the husband/wife and one dog. We haven't done any other lease since that time so they have been paying month to month. Now I realized that I had given them a long free ride and  I must do a new lease factoring how large the family have increased. I had been raising the rent each year by 5% and never had a problem with them. SO here are my questions:
1. Each time their payment arrive is after the 5th or 6th of the month even when the lease clearly said to be paid on the 1st of each month. So can I write a new lease saying that the rent must be pay in full on the 1st of each month and if check arrive after the 1st a penalty of $75 will be taken off their deposit and is that legal at all? OR just send then a bill right away for $75.00?
2. They are now paying $2,800.00 per month but I feel that they should be paying more. So how much more should I charge since the family has grown plus all the pets?

After their first child was born there had been more repair done at my home which I always pay for and there is more tear/wear/damage with all the walking running on the wood floor and carpet and the backyard. Plus all pets pee and poop inside homes.

Ideas?
TIA