BOTOX OR SOME KIND OF LINE FILLER.
IS IT SAFE
Your question is very hard to answer. Few of my friends were thinking the same thing while they were breastfeeding and they have been, usually, getting the same answer which was: consult your doctor.
Of course doctor is always going to say no to these things but if you go to the cosmetics clinic they will not send you away just because you are breastfeeding.
So the choice is entirely yours. You are probably aware that there are not so many studies or researches done on this subject because no woman is going to risk health of her child because of the Botox or filing. If you can wait I would suggest you to wait some time before you do anything that could possibly risk your child.