It is not uncommon for siblings to experience conflict or tension with one another, and there can be a variety of reasons why an older sister may feel resentment or dislike towards a younger sibling. However, it is important to recognize that each individual and relationship is unique, and it is not possible to accurately diagnose or understand the feelings of another person without directly communicating with them.

Some potential reasons that an older sister may feel resentment or dislike towards a younger sibling include:

1. Jealousy or competition: Siblings may feel jealous of one another if they perceive that the other is receiving more attention, resources, or privileges from their parents. This can be especially true if the younger sibling is perceived as being favored by the parents.
2. Different expectations or roles: In some families, older siblings may feel pressure to set an example for their younger siblings and may resent this responsibility. On the other hand, younger siblings may feel resentful if they are expected to follow rules or behave in a certain way because of their age or status as the younger sibling.
3. Personality or behavior differences: Differences in personality or behavior can also contribute to conflict between siblings. For example, an older sister may feel frustrated by a younger sibling who is perceived as being disruptive or disobedient.
4. Past conflicts or unresolved issues: Sometimes, past conflicts or unresolved issues between siblings can contribute to ongoing feelings of resentment or dislike. It may be helpful for siblings to work on resolving these issues through open and honest communication.

It is important to remember that siblings often have a complex and evolving relationship, and it is normal for there to be ups and downs. If you are concerned about your relationship with your older sister, it may be helpful to try to communicate with her directly and openly about your feelings. It may also be helpful to seek support from a trusted adult or a mental health professional.

In conclusion, there can be a variety of reasons why an older sister may feel resentment or dislike towards a younger sibling, including jealousy or competition, different expectations or roles, personality or behavior differences, and past conflicts or unresolved issues. It is important to communicate openly and honestly with one another and seek support when needed in order to work towards a positive and healthy relationship.