Is this food aggresion and a few other concerns

Morning all
Last night Tip growled at Robert when his leg accidently bumped against her. She has never done this before. I have stroked her while she was eating before without her making a sound she ignored me.

Our dogs get brown rice and pet mince mixed in their normal kibble once a week and that was last night's meal.

We been practising walking with the lead in the garden and it has been going okish with her only doing the pull and buck like a bronco twice but I would like to know how long and far we can start walking her.

We have play time in the garden twice a day other than the toilet trips
And she gets to play with the older dogs under supervision. My son's GSD and my daughter's cross JR get along with her just fine. The nine year old Rottie is stand ofish and gets growly when Tip wants to play. I been noticing that she been growly even with the older dogs aswell. She would sniff at Tip and walk away. No aggresion but she growls and pull up her lip if Tip wants to play. Is it just because she is a senior citizen that Sasha is acting like this?

In regards to walking, it is generally 2-3 walks a day at 5 minutes per month of age with some off lead time as well, I would suggest getting a long training lead that way Tip can get the playtime like off lead but you still can handle her in case.

Its great that you are socializing her and she is getting along with other dogs, but it may just be that the Rottie is not used to all the fun and play and that she is an older dog is just giving her a little warning, as long as its supervised play it should be fine!  Hope this helps x

Older dogs will often tell a the young whipper snappers off for getting in their face .... bad doggy manners are still not okay, even if you are a puppy!

Keep an eye on them when they are together (and never leave them along together when you are out etc!) .. you may find that after some time they become more settled together

Will do. We went for computer training today so Tip had to stay at home. My husband made her a run that she can be left outdoors when we have to go out and can't take her with us. It keeps her safely from the other dogs when we can't be home.

Also Sasha seem to be depressed since our other dog had to be put to sleep. She sometimes refuse to eat and seem to want to sleep more than everything else. Her hearing and sight is still fine, she just seem like she lost interest. She doesn't enjoy walking anymore either. Is there anything I can do to help her?