Noticed Movable, Painless Lymph Nodes On Sides Of Neck. Could It Be Lymphoma?

Question: Hi, my 6 year old daughter has palpable lymph nodes on both sides of her neck for almost four weeks now. They're bean-sized, pea-sized each side, movable, firm but not hard, painless. She had an UrI with low grade fever, malaise, sore throat, cough, rhinorrhea in july, and what looked like a viral pharyngitis is august (no fever, sore throat, rhinorrhea). Well, as soon as i noticed the nodes, I took her to a pediatrician that felt them and told me they were normal, especially since her recent (2 months) history of UrI. So I looked for a second opinion. the 2nd ped felt the nodes and said the same, but ordered a CBC, Sedimentation rate, urine and feces samples, Ebv, toxoplasmosis, CmV Serology. The only thing that came positive was the IgG for CMV - 186 titer. Everything looked fine. We did a neck ultrasound, an the radiologist (MD) told me that those were reactive nodes, up to 1.1 cm in the posteior cervical, and a 1.7 cm in her left submandibular area, all with beNign features (hillus, echogenicity, size and form - long/short ratio). It's been three weeks since the exam, the nodes are still there, doesn't seem to be getting any bigger- in fact, the last ped that saw her said the submandibular one doesn't feel like 1.7, but less. I took her to this third pediatrician, who looked at the exames and felt them, said there's nothing to be worried about. She's in great shape, eating well, active, not complaining of any kind of pain. She does in fact have a slightly rhinorrea, a ligth redish throat and she isn't complaining of it. She has actopic eczema due to milk allergy since a baby, seborrheic dematitis behind both ears every now and then. My question is: with the nodes staying this size for almost a month, being an actopic kid, positive for a chronic infection like CMV, having UrI in july-aug, with a normal ultrasound (the doctor didn't even feel that doppler was necessary), can we rule out lymphoma??? I'm so afraid... It's been three peds, a radiologist, and i can't calm down... Is it normal for this nodes to be like this since with so little Upper spiratory tract symptons/allergies?
I just felt them and they seem to be a little smaller, maybe the biggest one feels like a pea - at least a "smaller bean" a and the little one half-pea. She said it was painfull to touch, too. She seems to have a little running nose, dripping on the back of her mouth (oropharix?) and her tonsils are hyperemiated, but not really enlarged. The last ped prescribed amoxicilin for 10 days because of the submandibular node and the fact that my daughter had 3 cavitys that were taken care by our dentist 10 days before i first felled the lumps- that ended up sunday.
By the way, the lymph were never noticiable, just feeled, they were never that large. Oh, and I remembered one thing: her two best friends had a very strong sinus infection 1-2 weeks before I first noticed the nodes. Could it be that her lymph nodes were still enlarged from the past july-aug infections and just swollen a little bit because of the contact with her friends illnesses/virus/bacteria? She didn't "cath" it though?
I'm sorry, but i'm a very concerned mother,