It's been a challenge getting my kids to share but it's also been a great learning experience. My son adores his little sister but when it comes to sharing toys, it's survival of the fittest! Here's how we helped him with sharing;
1. Sharing is caring. 'You love your little sister right?'
2. Set a good example. 'If she doesn't learn to share from you, she'll learn NOT to share with you'.
3. When you share you get more; as in, 'when she gets new toys, she'll share those toys with you'.
4. Read books about sharing. ("Me To!" by Mercer Mayer is a fun book to read)
5. When hubby and I share (e.g. food), we drilled it in until he got the idea.