Have i given an overdose of Montek LC.

Hello doctor, my daughter is 4 years old and 32 kilos. She is being treated for lower respiratory tract infection. She was prescribed Azithral 200 syrup 5ml in the morning and 2.5ml in the night, Nebulizer Levolin 0.63 and budecort 0.5 along with Montek LC syrup (Levocetirizine and Montelukast) 5ml once a day. I was worried about one thing. I misread the prescription and gave my daughter 5.5ml of Montek LC syrup yesterday night and day before yesterday night instead of 5ml till I rechecked and saw the dosage was 5ml. I am worried if it will cause some issues to her kidneys or liver because of giving 0.5 ml extra syrup to her. She is not showing any signs of overdose like vomiting or nausea. She only slept for extra hours today and yesterday morning. She is running around and playful a always. Is there a cause for concern? Can an overdose show up later?