Here’s some suitable advice for each of the sentences:

1. **She is always playing games on her phone.**
- **Advice:** Encourage her to take regular breaks and try activities outside of gaming.

2. **It's a good idea for us to ride slowly in the rain.**
- **Advice:** Always prioritize safety by reducing speed and being cautious of slippery surfaces.

3. **Eating too much ice cream isn't good for children.**
- **Advice:** Promote moderation and suggest healthier snack alternatives.

4. **He looks tired.**
- **Advice:** Suggest he gets some rest and establishes a regular sleep schedule.

5. **Teenagers often stay up late.**
- **Advice:** Recommend setting a bedtime to ensure they get enough sleep for their health.

6. **Playing football on the pavement is very dangerous.**
- **Advice:** Encourage playing in safe areas like parks or sports fields to avoid injuries.