How to unable inappropriate ads on iPad while playing a game?

This is a user-to-user forum. You are not speaking to Apple here.

It is the app developer who is running this ad – or allowing some third-party advertising network to run it. You may want to contact the app developer, or stop using the offending app.

How to contact an app developer - Apple Support

You could also send feedback to Apple.

Product Feedback - Apple

What is the age setting you have for your child?

You can review the age ratings and content you may see here and adjust the age range to one you think is more appropriate for your child. For example, in the 12+ age rating, this is content you may see and it includes Frequent or intense profanity or crude humor. The ads in the game must also comply with this standard for the age rating of the game. If you find a game that includes ads that are not allowed in the ratings below, then they can be reported to Apple at the report a problem website and even contact the developer. Some parents restrict apps for a rating below the child's actual age and others allow apps with a higher age rating. There is no one standard that all parents find acceptable, so feel free to make the choice of what you want to allow:

Apps with this rating may contain instances of the following content that may not be suitable for children under the age of 12:

• Infrequent or mild medical or treatment-focused content
• Infrequent or mild references to alcohol, tobacco, or drug use
• Infrequent or mild sexual content or nudity
• Frequent or intense contests
• Frequent or intense profanity or crude humor
• Frequent or intense horror or fear themed content
• Frequent or intense cartoon or fantasy violence
• Infrequent or mild occurrences of realistic violence
• Infrequent or mild simulated gambling

Age ratings - Reference - App Store Connect - Help - Apple Developer

Yes, you can contact the developer (How to contact an app developer - Apple Support), give feedback, or… just not let your daughter play the game.

Let me know if you need more help!