1. Prepare the Strawberries:
   - If using fresh strawberries, wash them thoroughly under cold water.
   - Remove the stems and any leaves.
   - Cut the strawberries into small pieces.
2. Prepare the Peaches:
   - If using fresh peaches, gently peel off the skin and remove the pit.
   - Cut the peaches into smaller chunks.
   - If using canned peaches, drain them and give them a quick rinse under cold water.
3. Blend the Ingredients:
   - Place both the strawberry pieces and the peach chunks into a blender or baby food processor.
   - Blend until you achieve a smooth, lump-free puree. If the mixture is too thick, you can add a small amount of water or the natural juice from the canned peaches (if using) to reach the desired consistency.
4. Serve:
   - Spoon the puree into a baby bowl and allow it to cool to an appropriate temperature before feeding.

Summary:
This Strawberry and Peach Baby Puree is nutritious and delicious, providing essential vitamins and natural sugars required for a growing baby. The strawberries are rich in vitamin C, while peaches are a great source of vitamin A and dietary fiber. This puree is smooth, easy to digest, and perfect for a baby aged 4-10 months.

Storing Options:
- You can store any leftovers in an airtight container in the refrigerator for up to 48 hours.
- For longer storage, you can freeze the puree in baby food containers or ice cube trays. Simply thaw in the refrigerator overnight or gently warm in a water bath before serving.

Possible Side Effects/Allergies:
- Always introduce new foods one at a time to detect any allergic reactions.
- Strawberries can sometimes cause a rash around the mouth, especially if your baby has sensitive skin. Watch for any signs of allergic reactions such as rash, swelling, or digestive issues.
- Peaches are typically well-tolerated but always monitor the baby after feeding for any unusual reactions.