Nelly is 4 months now and teething and getting bored very quickly and easily however much a play with her, train her and walk her. What are safe things for her to chew that will keep her busy. Human food? Marrow bones?
Personally I would get a couple of kongs and freeze them full of her favourite food. A few ideas are kibble soaked in water, mashed banana, sardines. Not only will it help with her teeth but it will keep her safely occupied.
Along with Kongs you could try frozen carrots, rice bones (these can be frozen too), knot a wet tea towel and freeze it. Also, plastic bottles with a few bits of kibble are great fun, but noisy! My favourite at this age was to use a kong wobbler and feed all meals in it, outside if possible.
We did frozen (and non frozen) carrots, frozen chicken wings, ice cubes, plastic bottle inside an old sock (that lasted ages), rice bones, cardboard boxes, cardboard tubes (like those you get in kitchen rolls). Although Bailey's personal favourite was (and still is if I am not quick enough or careless) my hairbrush - I am now on hairbrush number 2 after loosing number 1 and finding it in bits - literally about a million bits - even number two has teeth marks in the handle (due to me putting the brush down to tie my hair up, Bailey putting his head lovingly on my knee, then woosh it's gone!
My pups love the teething sticks by Kong which are available in 3 sizes. The ribbing seem to give them lots of surface on sore gums https://www.amazon.co.uk/gp/aw/d/B0...490706070&sr=8-1&keywords=kong+teething+stick
When he was tiny I used to chop the carrots into sticks for the fresh carrot but the frozen one I gave whole. He only had them supervised. Bailey always has had a cast iron stomach but I never have and still do not give him anything in excess. He is now fed raw and he loves cooked carrots mixed into his meals.