So like a philter that can be used on female pets to specificly get a gendered egg out of them.

Some restrictions:
Mother has to be unbred befor philter is used.
There are two philters, one for male only offspring, one for female only offspring.
Scale shop or diamond shop item ( non traidable and vary expensive)
Philter has a set amout of uses (ex: only effects first 100 offspring)

Give me your thougbts guys :)

That sounds good, however there's a con to this:
People who are poor/don't have time won't be able to buy these
And people who brought diamonds with their own money (cash) wold be angry to see that the potion is out of use

Instead:
the one's that cost diamonds can be a good amount of off spring (around 500-1000) and the special one's that could be infinite offspring come in the events

Personally I don't even breed maybe 20 eggs from a single Sylesti, so perhaps for the non mass breeders a lesser version?
Also, I don't really see the point of restricting the mother to not having bred before, it doesn't really change anything about previous offspring it may have had before.