I strongly believe that pets must be part from every family

I have been having cat since 5 years. Her name is Jess and I love her. She is cute, lovable and friendly, she is like my little sister that I do not have. Also the old people have said "The dog is your best friend". These are only two of all reasons why in my opinion pets must be like part of your family. In the following passage I will show you some other.

First of all, pets cannot speak. This means that they can hurt you with their words like many people do in your busy daily routine. Everyone, who has a pet in home, knows that when he or she comes home after work will receive only sweet mew from his/her cat or slipper close to the door from the dog. Every day after school I know that when I go home will see her and she will stay next to my when I make my homework. She looks just like she supports my.

Second, one pet must be treated like a family member, because there are many couples that live together and in one moment they want to have children, but if they are not sure in themselves, because one baby wants care, they take a pet. The pets in this case are like an exercise before the babies. On first place you must feed them. Also you must clean after them. The dogs need to go for a walk in the park for example. This is just like my sister and her husband did. They have wanted to have kids, but she was not sure if she had enough time for them. They have been having cat since 3 years and my little nephew since 2 years. This is the perfect example how pets can help you.

The pets are just perfect. On one hand when you can spend your free time with them, to relax with them. But also to make a preparation for your future kids for example. It has many different reasons about my choice. That is way I strongly believe that pets must be part from every family.

I have been having cat since 5 years. I have a cat since 5 since years. You can omit been and having

She is cute, lovable and friendly, she is like my little sister that I do not have. Run-on

Also the old people have said "The dog is your best friend". I don't get it. You said cat and now it's dog. Your world "also" have no reference.

Everyone, who has a pet in home, knows that when he or she comes home Remove the commas. I reckon this is not a participial phrase.

On one hand when you can spend your free time with them, to relax with them. Remove the on one hand. There are no other hands (ideas).

Your thoughts and grammar are crumpled. Review your work.

Thanks a lot for your advises. :))

I think "having" is not the best word there... just use "owned."
I have owned a cat for...

Use "and"
She is cute, lovable and friendly, and she is like my little sister that I do not have.

I'll make a lot of changes to this part, and you tell us if you have questions about them:
On one hand, you can spend your free time with them, to relax with them, but also the effort to care for them helps you make preparation for caring for your future kids, for example. I hold this view for many different reasons. That is way I strongly believe that pets must be part of every family.